Method and end assembly for welding device

ABSTRACT

An end assembly for use with a welding device having a chamber between the diffuser sleeve and the insert which allows for cooling the insert and for controlling the flow of gas through the end assembly. Some of the components of the end assembly such as the contact tip, insert and gooseneck are constructed of a conductive material which are securely held together in contact by a diffuser sleeve constructed of a dissimilar material. The end assembly provides better conductivity of the current through the end assembly for use of less energy during welding.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Application No. 17/556,415,filed Dec. 20, 2021, which is a continuation of U.S. Application No.14/667,234 filed on Mar. 24, 2015, now U.S. Patent No. 11,203,079, whichis a continuation-in-part of U.S. Application No. 14/224,942 filed onMar. 25, 2014, now U.S. Pat. No. 9,950,386, which are herebyincorporated herein by reference in their entirety, except that thepresent application supersedes any portion of the above referencedapplication which is inconsistent with the present application.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTINGCOMPACT DISC APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an end assembly for use in a weldingdevice. In particular, the present invention relates to end assemblyhaving an insert for controlling the flow of gas during welding. Furtherthe present invention relates to a method for controlling the flow ofgas to cool the welding device.

Metal Inert Gas (MIG) welding also referred to as “wire-feed” or GasMetal Arc Welding (GMAW) utilizes heat from an electrical arc to melt aconsumable electrode to form a weld on a workpiece. A MIG welding systemtypically includes a power supply, a gas supply and an electrode supplyconnected to a welding device or welding gun. A ground cable is used toconnect the workpiece to the power supply. The welding device generallyincludes a handle, a gooseneck and an end assembly. The welding systemcan be automatic or semi-automatic and may be manually or roboticallycontrolled. The electrode and gas are coupled through a conduit in thehandle and the gooseneck to the end assembly of the welding device. Theelectrode extends through the contact tip of the end assembly and thegas moves around the contact tip in the nozzle of the end assembly. Whenthe welding device is activated, the electrode is fed through thecontact tip toward the workpiece and the gas is directed through thenozzle towards the workpiece. When the electrode is placed adjacent orin contact with the workpiece, the electrode completes an electricalcircuit between the power supply and the workpiece allowing current toflow through the electrode to the workpiece. The current produces an arcbetween the electrode and the workpiece. The heat of the arc melts theelectrode and the workpiece in the region surrounding the arc creating aweld puddle. The gas flowing out the nozzle shields the weld puddle fromoutside contaminants. The type of gas used in MIG welding variesdepending on many factors. Noble or inert gases such as Argon are oftenused. However, Carbon Dioxide (CO₂) and a mixture of gases such as CO₂and Argon are also used. Once the electrode is moved away from theworkpiece, the electric circuit is broken and the weld puddle cools andsolidifies forming a weld.

There remains a need for an end assembly for a welding device whichallows for better control of the flow of gas around the weld puddle andwhich reduces the energy used during welding by providing consistentcurrent flow.

BRIEF SUMMARY OF THE INVENTION

The end assembly of the present invention is used with a welding devicefor GMAW. In one embodiment, the end assembly includes a gooseneck, adiffuser sleeve, an insert, a contact tip and a nozzle. The componentsof the end assembly are secured together so as to share a common axis.The insert has an inner passageway and a wall extending between theends. The wall has at least one hole in fluid communication with theinner passageway. The diffuser sleeve has an inner cavity and a wallextending between the ends. The wall has at least one hole in fluidcommunication with the inner cavity. The insert is positioned in theinner cavity of the diffuser sleeve spaced between the gooseneck and thecontact tip. The wall of the insert and the wall of the diffuser sleeveare axially adjacent along the longitudinal axis of the end assembly andare spaced apart in a direction essentially perpendicular to thelongitudinal axis of the end assembly so that a chamber is formedbetween the wall of the insert and the wall of the diffuser sleeve. Thehole in the wall of the diffuser sleeve and the hole in the wall of theinsert are in fluid communication with the chamber.

In a second embodiment, the end assembly includes a gooseneck, adiffuser, a diffuser sleeve, a contact tip, and a nozzle. In thisembodiment, the diffuser is secured on the second end of the gooseneck.The components of the end assembly are secured together so as to share acommon axis. The diffuser has an inner passageway and a wall extendingbetween the ends. The wall has at least one hole in fluid communicationwith the inner passageway. The diffuser sleeve has an inner cavity and awall spaced between the ends. The wall of the diffuser sleeve has atleast on hole in fluid communication with the inner cavity. The diffuseris positioned in the inner cavity of the diffuser sleeve so that thewall of the diffuser and the wall of the diffuser sleeve are positionedessentially axially adjacent along the longitudinal axis of the endassembly. The wall of the diffuser and the wall the diffuser sleeve arespaced apart in a direction essentially perpendicular to thelongitudinal axis of the end assembly so that a chamber is formedbetween the wall of the diffuser and the wall of the diffuser sleeve.The hole in the wall of the diffuser sleeve and the hole in the wall ofthe diffuser are in fluid communication with the chamber.

The chamber can have a variety of shapes and sizes. In one embodiment, asize of the chamber varies along the axial length of the chamber betweenthe ends of the chamber. In one embodiment, a length of the chamberbetween the ends varies. In one embodiment, the chamber is tapered alongthe axial length of the chamber so that a size or diameter of thechamber adjacent the first end of the diffuser sleeve is less than asize or diameter of the chamber adjacent the second end of the diffusersleeve. In one embodiment, the hole or holes in the wall of the diffusersleeve is axially misaligned along the longitudinal axis of the endassembly with the hole or holes in the wall of the insert or in thediffuser. In one embodiment, a diameter of the hole or holes in thewalls of the insert or in the diffuser are not equal to a diameter ofthe hole or holes in the wall of the diffuser sleeve. In one embodiment,a diameter of the hole or holes in the walls of the insert or in thediffuser are equal to a diameter of the hole or holes in the wall of thediffuser sleeve.

In use, the gas flows from the gas supply through the passageway of thegooseneck into the inner passageway of the insert or diffuser. The gasflows to the diffuser section of the inner passageway and exits theinner passageway into the chamber through the hole or holes in the wallof the insert or in the diffuser. The gas is held or trapped in thechamber and moves in the chamber. In one embodiment, the velocity of thegas in the chamber is changed and controlled. In one embodiment, thechamber changes a velocity of the gas so that a velocity of the gasexiting the chamber is different from a velocity of the gas entering thechamber. In one embodiment, a velocity of the gas is changed by changinga diameter of the hole or holes in the wall of the insert or in thediffuser. In one embodiment, a velocity of the gas exiting the chamberis changed by changing a diameter of the hole or holes in the wall ofthe diffuser sleeve. In one embodiment, a velocity of the gas exitingthe chamber is changed by changing a position of the hole or holes inthe wall of the insert or in the wall of the diffuser. In oneembodiment, a velocity of the gas exiting the chamber is changed bychanging a position of the hole or holes in the wall of the diffusersleeve. In one embodiment, a velocity of the gas in the chamber andexiting the chamber is changed by changing the number of holes in thewall of the insert or in the wall of the diffuser. In one embodiment, avelocity of the gas exiting the chamber is changed by changing thenumber of holes in the wall of the diffuser sleeve. In one embodiment,the movement of the gas in the chamber and exiting the chamber iscontrolled by changing the size of the chamber, or changing the positionof the hole or holes in the wall of the insert or the diffuser, orchanging the position of the hole or holes in the wall of the diffusersleeve, or changing the number or diameter of the hole or holes in thewall of the insert or in the diffuser or changing the number or diameterof the hole or holes in the wall of the diffuser sleeve. The chamberallows for controlling the flow of gas through the end assembly. The gasexits the chamber though the hole or holes in the wall of the diffusersleeve into the gas channel of the nozzle. The gas moves along the gaschannel to the second end of the nozzle to the work piece. Controllingthe flow of the gas reduces contaminants in the weld puddle allowing fora better weld. The shape of the gas channel of the nozzle and the shapeof the contact tip can be adjusted to control the flow of gas around theweld puddle. Controlling the gas also reduces the amount of gas usedduring welding. The gas trapped in the chamber also acts to cool theinsert or the diffuser. Cooling the insert or the diffuser also pullsheat away from the contact tip to reduce damage to the contact tip fromheat during welding to extend the useful life of the contact tip. In oneembodiment, the second end of the insert has an indention with an innersurface and the first end of the contact tip has a radiused end surfaceand the first end of the contact tip extends into the indention so thatthe radiused end surface of the contact tip is in contact with the innersurface of the indention to provide better contact between the insertand the contact tip for better heat transfer and for better currentconductivity. In one embodiment the contact tip is threaded into thesecond end of the diffuser sleeve and the second end of the gooseneck isthreaded into the first end of the diffuser sleeve and the insert isspaced between and in contact with the contact tip and the gooseneck andthe diffuser sleeve securely holds the gooseneck, insert and contact tipin position and in secure constant contact.

In one embodiment, the second end of the gooseneck, the insert and thecontact tip are constructed of a conductive material and the diffusersleeve is constructed on a poorly conductive or non-conductive materialor a material that is less conductive than the material or materialsused to construct the insert or the contact tip. In one embodiment, ofthe second embodiment, the gooseneck, the diffuser and contact tip areconstructed of a conductive material and the diffuser sleeve isconstructed of a poorly conductive or non-conductive material or amaterial that is less conductive than the material or materials used toconstruct the insert or the contact tip. In one embodiment, of the thirdembodiment, the insert and the contact tip are constructed of aconductive material and the diffuser base and the diffuser sleeve areconstructed of a poorly conductive or non-conductive material or amaterial that is less conductive than the material or materials used toconstruct the insert or the contact tip. The diffuser sleeve securelyholds the second end of the gooseneck, the insert and the contact tip intight, secure contact so that the components do not move duringwelding., In the second embodiment the diffuser sleeve securely holdsthe second end of the gooseneck, the diffuser and the contact tip intight, secure contact so that the components do not move during welding.In the third embodiment, the diffuser sleeve holds the insert and thecontact tip in tight, secure contact so that the components do not moveduring welding. The tight, secure contact between the conductivegooseneck, the insert and the contact tip or in the second embodiment,the gooseneck, the diffuser and the contact tip allows for a constantcurrent flow through the end assembly with less resistance and lessimpedance. The constant current flow allows for consistent arc startsduring welding and reduces the energy used during welding. In oneembodiment, the insert and the contact tip are constructed of a materialdissimilar to the material used to construct the diffuser sleeve. In thesecond embodiment, the diffuser and the contact tip are constructed of amaterial dissimilar to the material used to construct the diffusersleeve. In the third embodiment, the insert and contact tip areconstructed of a material dissimilar to the material used to constructthe diffuser sleeve and the diffuser base. The use of dissimilarmaterials allows for a tighter connection between the contact tip andinsert by reducing the temperature of the components during weldingwhich prevents fusing of the contact tip and insert or the contact tipand diffuser with the diffuser sleeve during welding. In one embodiment,the second end of the gooseneck, the insert and the contact tip areconstructed of copper and the diffuser sleeve is constructed of brass.In the second embodiment, the gooseneck, the diffuser and the contacttip are constructed of copper and the diffuser sleeve is constructed ofbrass. In the third embodiment, the insert and contact tip areconstructed of copper and the diffuser sleeve and the diffuser base areconstructed of brass.

The present invention relates to an end assembly for a welding devicecomprising, a gooseneck having a passageway, a diffuser sleeve having afirst end and a second end with an longitudinal axis extendingtherebetween, having an inner cavity and having a wall having a hole,the diffuser sleeve connected to the gooseneck, an insert having aninner passageway and a wall having a hole, the insert positioned in theinner cavity of the diffuser sleeve with the wall of the insert axiallyadjacent and spaced apart from the wall of the diffuser sleeve forming achamber positioned between the wall of the insert and the wall of thediffuser assembly so that the hole in the wall of the diffuser sleeveand the hole in the wall of the insert are in fluid communication withthe chamber; a contact tip positioned in the inner cavity of thediffuser sleeve so that the contact tip extends into the inner cavity ofthe diffuser sleeve and extends outward from the diffuser sleeve in adirection opposite the insert; and a nozzle having a gas channel andconnected to the diffuser sleeve, the nozzle extending outward from thediffuser sleeve in a direction opposite the gooseneck.

Further, the present invention relates to a diffuser assembly for use ina welding device comprising a diffuser sleeve having a first end and asecond end with an longitudinal axis extending therebetween, having awall with a hole and having an inner cavity; an insert having a wallwith a hole and an inner passageway, the insert positioned in the innercavity of the diffuser sleeve with the wall of the insert axiallyadjacent and spaced apart from the wall of the diffuser sleeve forming achamber positioned between the wall of the insert and the wall of thediffuser sleeve so that the hole in the wall of the diffuser sleeve andthe hole in the wall of the insert are in fluid communication with thechamber.

Still further, the present invention relates to a an end assembly for awelding device comprising a gooseneck having a passageway; a diffuseradjacent the gooseneck, the diffuser having a wall with a hole and aninner passageway in fluid communication with the passageway of thegooseneck; a diffuser sleeve having a first end and a second end with anlongitudinal axis extending therebetween, the diffuser sleeve having awall with a hole and having an inner cavity, the diffuser sleeveconnected at the first end to gooseneck with the diffuser positioned inthe inner cavity and the wall of the diffuser axially adjacent andspaced apart from the wall of the diffuser sleeve forming a chamberpositioned between the wall of the diffuser and the wall of the diffusersleeve so that the hole in the wall of the diffuser sleeve and the holein the wall of the diffuser are in fluid communication with the chamber;and a contact tip configured to extend into the inner cavity of thediffuser sleeve at the second end of the diffuser sleeve.

Further still, the present invention relates to a combination contacttip and diffuser assembly for a welding device, the combinationcomprising, the diffuser assembly having a diffuser sleeve having afirst end and a second end with an longitudinal axis extendingtherebetween, having a wall with a hole and having an inner cavity, thediffuser assembly having an insert with a first end and a second end,the second end having an indention with a radiused inner surface, theinsert having a wall with a hole and having an inner passageway, theinsert positioned in the inner cavity of the diffuser sleeve with thewall of the insert axially adjacent and spaced apart from the wall ofthe diffuser sleeve forming a chamber positioned between the wall of theinsert and the wall of the diffuser sleeve so that the hole in the wallof the diffuser sleeve and the hole in the wall of the insert are influid communication with the chamber; and the contact tip having a firstend and a second end with a center bore extending therethrough, thefirst end having a radiused outer surface, the contact tip inserted inthe inner cavity of the diffuser sleeve at the second end of thediffuser sleeve so that the outer surface of the first end of thecontact tip extends into the indention in the second end of the insertand the end surface of the contact tip abuts the inner surface of theinsert and the center bore of the contact tip is aligned with the innerpassageway of the insert.

Further still, the present invention relates in one embodiment, to acontact tip for a welding device comprising a radiused or rounded orconvex curved first end and a radiused second end with a center boreextending there through and having buttress threads spaced apart fromsecond end. In one embodiment, the second end of the diffuser sleeve hasbuttress threads with mate with the buttress threads of the contact tip.In one embodiment, the contact tip has four buttress threads.

Still further, the present invention relates to a method for controllinga flow of gas in a welding device comprising the steps of providing agas supply; providing a welding gun having an end assembly, the endassembly having a gooseneck with a passageway, a diffuser sleeveconnected to the gooseneck having a first end and a second end with anlongitudinal axis extending therebetween, the diffuser sleeve having aninner cavity and having a wall with a hole, an insert positioned in theinner cavity of the diffuser sleeve and having an inner passageway and awall having a hole, the wall of the insert axially adjacent and spacedapart from the wall of the diffuser sleeve forming a chamber positionedbetween the wall of the insert and the wall of the diffuser assembly sothat the hole in the wall of the diffuser sleeve and the hole in thewall of the insert are in fluid communication with the chamber; acontact tip positioned in the inner cavity of the diffuser sleeve sothat the contact tip extends into the inner cavity of the diffusersleeve and extends outward from the diffuser sleeve in a directionopposite the insert; and a nozzle having a gas channel and connected tothe diffuser sleeve, the nozzle extending outward from the diffusersleeve in a direction opposite the gooseneck; supplying the gas to thepassageway of the gooseneck so that the gas moves though passageway ofgooseneck to the inner passageway of the insert though the hole in thewall of the insert and into the chamber; controlling the gas in thechamber; and controlling the gas exiting the chamber through the hole inthe diffuser sleeve and through the gas channel of the nozzle.

Further still, the present invention relates to a method for controllinga flow of gas in a welding device comprising the steps of providing agas supply; providing a welding gun having a gooseneck with apassageway, diffuser connected to the gooseneck, the diffuser having awall with a hole and an inner passageway in fluid communication with thepassageway, a diffuser sleeve having a first end and a second end withan longitudinal axis extending therebetween, having a wall with a holeand having an inner cavity, the diffuser sleeve connected to gooseneckwith the diffuser positioned in the inner cavity and the wall of thediffuser axially adjacent and spaced apart from the wall of the diffusersleeve forming a chamber positioned between the wall of the diffuser andthe wall of the diffuser sleeve with the hole in the wall of thediffuser sleeve and the hole in the wall of the diffuser in fluidcommunication with the chamber, a contact tip configured to extend intothe inner cavity of the diffuser sleeve; and a nozzle having a gaschannel and configured to connect to the gooseneck and extend outwardalong the contact tip; supplying the gas to the passageway of thegooseneck so that the gas moves though passageway of gooseneck to theinner passageway of the diffuser though the hole in the wall of thediffuser into the chamber; controlling the gas in the chamber; andcontrolling the gas exiting the chamber through the hole in the diffusersleeve and through the gas channel of the nozzle.

Still further, the present invention relates to a method for cooling acontact tip of a welding device which comprises the steps of providing agas supply; providing an end assembly having a diffuser sleeve with afirst end and a second end extending along a longitudinal axis, thediffuser sleeve having a wall with a hole and having an inner cavity; aninsert having a wall with a hole and an inner passageway, the insertpositioned in the inner cavity of the diffuser sleeve with the wall ofthe insert axially adjacent and spaced apart from the wall of thediffuser sleeve forming a chamber positioned between the wall of theinsert and the wall of the diffuser sleeve so that the hole in the wallof the diffuser sleeve and the hole in the wall of the insert are influid communication with the chamber; providing a contact tip in contactwith an insert; moving gas from the gas supply into the end assembly andinto the inner passageway of the insert and through the hole in theinsert and into the chamber; temporarily trapping the gas in thechamber; controlling the gas in the chamber to cool the insert and thecontact tip; and moving the gas out of the chamber through the hole inthe diffuser sleeve.

Further still, the present invention relates to a method for cooling acontact tip of a welding device which comprises the steps of providing agas supply; providing a gooseneck having a passageway, a diffuserconnected to the diffuser, the diffuser having a wall with a hole and aninner passageway in fluid communication with the passageway, a diffusersleeve having a first end and a second end with an longitudinal axisextending therebetween, having a wall with a hole and having an innercavity, the diffuser sleeve connected to gooseneck with the diffuserpositioned in the inner cavity and the wall of the diffuser axiallyadjacent and spaced apart from the wall of the diffuser sleeve forming achamber positioned between the wall of the diffuser and the wall of thediffuser sleeve with the hole in the wall of the diffuser sleeve and thehole in the wall of the diffuser in fluid communication with thechamber; providing a contact tip in contact with the diffuser; movinggas from the gas supply into the passageway of the gooseneck and intothe inner passageway of the diffuser and through the hole in thediffuser and into the chamber; temporarily trapping the gas in thechamber; moving the gas in the chamber to cool the diffuser and thecontact tip; and moving the gas out of the chamber through the hole inthe diffuser sleeve.

In one embodiment, the hole in the wall of the diffuser sleeve isaxially misaligned with the hole in the wall of the insert. In oneembodiment, a diameter of the hole in the wall of the diffuser sleeve isgreater than a diameter of the hole in the wall of the insert. In oneembodiment, a size of the chamber varies along the length. In oneembodiment, the size of the chamber at the first end is less than thesize of the chamber at the second end. In one embodiment, the outersurface of the wall of the insert is angled. In one embodiment, adiameter of the chamber varies along the length of the chamber. In oneembodiment, the diameter of the chamber at the first end is greater thana diameter of the chamber at the second end. In one embodiment, thesecond end of the insert has an indention with a radiused inner surfaceand the contact tip has a first end with a radiused end surface and thefirst end of the contact tip extends into the indention in the secondend of the insert so that the radiused end surface of the contact tipabuts the radiused inner surface of the insert. In one embodiment, theinsert is constructed of a conductive material, the contact tip isconstructed of a conductive material and the diffuser sleeve isconstructed of a poorly conductive, less conductive or non-conductivematerial and the insert is in contact with the contact tip. In oneembodiment, the end of the gooseneck is constructed of a conductivematerial and extends into the inner cavity of the diffuser sleeve andinto contact with the insert. In one embodiment, the insert isconstructed of copper, the contact tip is constructed of copper, the endof the gooseneck is constructed of copper and the diffuser sleeve isconstructed of brass and the end of the gooseneck extends into the innercavity of the diffuser sleeve and into contact with the insert and theinsert is in contact with the contact tip. In one embodiment, thegooseneck has an inner conduit constructed of copper and the innerconduit is in contact with the insert. In one embodiment, the insert isconstructed of copper, the contact tip is constructed on copper and thediffuser sleeve is constructed of brass and the insert is in contactwith the contact tip. In one embodiment, the insert and the contact tipare constructed of a material dissimilar to the material used toconstruct the diffuser sleeve. In one embodiment, the gooseneck has aninner conduit constructed of copper and the inner conduit is in contactwith the insert. In one embodiment, the insert is axially positioned inthe inner cavity of the diffuser sleeve between the gooseneck and thecontact tip. In one embodiment, the insert is axially secured and fixedin the inner cavity of the diffuser sleeve between the gooseneck and thecontact tip. In one embodiment, the insert has a first end and a secondend and the gooseneck contacts the first end of the insert and thecontact tip contacts the second end of the insert. In one embodiment,the insert is constructed of copper, the contact tip is constructed ofcopper and the diffuser sleeve is constructed of brass and the insert isin contact with the contact tip. In one embodiment, the gooseneck has aninner conduit constructed of copper and the inner conduit is in contactwith the insert. In one embodiment, the welding device has a gooseneckhaving an end constructed of a conductive material and a contact tip,the end of the gooseneck extends into the inner cavity of the diffusersleeve at the first end of the diffuser sleeve and contacts the insertand wherein the contact tip extends into the inner cavity of thediffuser sleeve at the second end of the diffuser sleeve and contactsthe insert. In one embodiment, the contact tip is constructed of aconductive material. In one embodiment, the insert is constructed ofcopper and the diffuser sleeve is constructed of brass. In oneembodiment, the welding device has a gooseneck having an end constructedof copper and a contact tip, the end of the gooseneck extends into theinner cavity of the diffuser sleeve at the first end of the diffusersleeve and contacts the insert and the contact tip extends into theinner cavity of the diffuser sleeve at the second end of the diffusersleeve and contacts the insert. In one embodiment, the contact tip isconstructed of copper. In one embodiment, the inner cavity of thediffuser sleeve has threads and the contact tip is threaded into theinner cavity of the diffuser sleeve at the second end of the diffusersleeve. In one embodiment, the welding device has a contact tip having afirst end with a radiused end surface, the insert has a first end and asecond end, the second end having an indention with a radiused innersurface and the first end of the contact tip extends into the indentionin the second end of the insert so that the radiused end surface of thecontact tip abuts the radiused inner surface of the insert. In oneembodiment, the hole in the wall of the diffuser sleeve is axiallymisaligned with the hole in the wall of the diffuser. In one embodiment,a diameter of the hole in the wall of the diffuser sleeve is greaterthan a diameter of the hole in the wall of the diffuser. In oneembodiment, the chamber has opposed first and second ends with a lengthbetween ends and a size of the chamber varies along the length. In oneembodiment, the first end of the chamber is adjacent the first end ofthe diffuser sleeve and the size of the chamber at the first end is lessthan the size of the chamber at the second end. In one embodiment, thewall of the diffuser has an outer surface and the outer surface of thewall is angled. In one embodiment, the chamber has opposed first andsecond ends extending along the axis of the diffuser sleeve with alength between ends and a diameter of the chamber varies along thelength. In one embodiment, a diameter of the chamber at the first end isgreater than a diameter of the chamber at the second end. In oneembodiment, the first end of the chamber is adj acent the first end ofthe diffuser sleeve. In one embodiment, the diffuser is constructed ofcopper, the contact tip is constructed of copper and the diffuser sleeveis constructed of brass and the diffuser is in contact with the contacttip. In one embodiment, the diffuser and contact tip are constructed ofa material dissimilar to the material used to construct the diffusersleeve. In one embodiment, the gooseneck has an inner conduitconstructed of copper and the diffuser is in contact with inner conduit.In one embodiment, the diffuser and the inner conduit are a singleintegral piece. In one embodiment, the gooseneck extends into the innercavity of the diffuser sleeve at the first end of the diffuser sleeveand the inner cavity of the diffuser sleeve has threads and wherein thecontact tip is threaded into the inner cavity of the diffuser sleeve atthe second end of the diffuser sleeve. In one embodiment, the innercavity of the diffuser sleeve at the second end is configured to receivebuttress threads, the first end of the contact tip has buttress threadsand the contact tip is threaded into the inner cavity of the diffusersleeve. In one embodiment, the wall of the insert has an outer surfaceand wherein the outer surface of the wall is angled. In one embodiment,the chamber has opposed first and second ends extending along the axisof the diffuser sleeve with a length between ends and a diameter of thechamber varies along the length. In one embodiment, the insert isconstructed of copper, the contact tip is constructed on copper and thediffuser sleeve is constructed of brass. In one embodiment, the weldingdevice has a gooseneck having an end constructed of copper, thegooseneck extends into the inner cavity of the diffuser sleeve at thefirst end of the diffuser sleeve and the end of the gooseneck contactsthe insert. In one embodiment, the contact tip has a first end andsecond end and the second end has a radiused outer surface, the nozzlehas a first end and a second end, the first end of the contact tip isadjacent the first end of the nozzle and the gas moves in the gaschannel from the first end to the second end of the nozzle and theradiused outer surface of the second end of the contact tip reduces adisturbance of the gas as the gas flows around the second end of thecontact tip. In one embodiment, the velocity of the gas in the chamberis controlled. In one embodiment, the gas is controlled by selecting aposition of the hole in the wall of the insert so that the hole in thewall of the insert is axially misaligned with the hole in the wall ofthe diffuser sleeve. In one embodiment, the gas is controlled bychanging a size of the chamber. In one embodiment, the gas is controlledby selecting a position of the hole in the wall of the insert so thatthe hole in the wall of the insert is axially misaligned with the holein the wall of the diffuser sleeve. In one embodiment, the gas iscontrolled by adjusting a size of the chamber. In one embodiment, thechamber has opposed first and second ends with a length between ends andthe gas is controlled by tapering the chamber along the length of thechamber. In one embodiment, the chamber has opposed first and secondends having an axial length therebetween and the gas is controlled byvarying a diameter of the chamber along the axial length of the chamber.In one embodiment, the first end of the chamber is adjacent thegooseneck and opposite the insert and the gas is controlled by taperingthe chamber so that a diameter of the chamber at the first end is lessthan a diameter of the chamber at the second end. In one embodiment, thegas is controlled by adjusting a size of the hole in the wall of theinsert. In one embodiment, the gas exiting the chamber is controlled byadjusting a size of the hole in the wall of the diffuser sleeve. In oneembodiment, the gas is controlled by selecting a size of the hole in thewall of the insert and selecting the size of the hole in the diffusersleeve so that the size of the hole in the wall of the insert is notequal to the size of the hole in the diffuser sleeve. In one embodiment,the gas is controlled by selecting the size of the hole in the wall ofthe insert so that the size of the hole in the wall of the insert isless than the size of the hole in the wall of the diffuser sleeve. Inone embodiment, the gas is controlled by adjusting a position of thehole in the wall of the insert. In one embodiment, the gas is controlledby providing more than one hole in the insert. In one embodiment, thegas exiting the chamber is controlled by providing more than one hole inthe diffuser sleeve. In one embodiment, a velocity of the gas exitingthe chamber is controlled. In one embodiment, the contact tip has afirst end and second end and the second end has a radiused outersurface, the nozzle has a first end and a second end, the first end ofthe contact tip is adjacent the first end of the nozzle and the gasmoves in the gas channel from the first end to the second end of thenozzle and the radiused outer surface of the second end of the contacttip reduces a disturbance of the gas as the gas flows around the secondend of the contact tip. In one embodiment, a velocity of the gas in thechamber is controlled. In one embodiment, the gas is controlled byselecting a position of the hole in the wall of the diffuser so that thehole in the wall of the diffuser is axially misaligned with the hole inthe wall of the diffuser sleeve. In one embodiment, the gas iscontrolled by selecting a position of the hole in the wall of thediffuser so that the hole in the wall of the diffuser is axiallymisaligned with the hole in the wall of the diffuser sleeve. In oneembodiment, the chamber has opposed first and second ends having anaxial length therebetween and the gas is controlled by varying adiameter of the chamber along the axial length of the chamber. In oneembodiment, the second end of the chamber is adjacent the contact tipand the gas is controlled by tapering the chamber so that a diameter ofthe chamber at the second end is greater than a diameter of the chamberat the first end. In one embodiment, the gas is controlled by adjustinga size of the hole in the wall of the diffuser. In one embodiment, thegas exiting the chamber is controlled by adjusting a size of the hole inthe wall of the diffuser sleeve. In one embodiment, the gas iscontrolled by selecting a size of the hole in the wall of the diffuserand a selecting a size of the hole in the diffuser sleeve so that a sizeof the hole in the wall of the diffuser is not equal to the size of thehole in the diffuser sleeve. In one embodiment, the gas is controlled byselecting the size of the hole in the wall of the diffuser so that thesize of the hole in the wall of the diffuser is less than the size ofthe hole in the wall of the diffuser sleeve. In one embodiment, the gasis controlled by adjusting a position of the hole in the wall of thediffuser. In one embodiment, the gas is controlled by providing morethan one hole in the diffuser. In one embodiment, a velocity of the gasexiting the chamber is controlled. In one embodiment, the insert has afirst and second end and the second end of the insert has an indentionwith a radiused inner surface and the contact tip has a first and secondend, the first end having a radiused end surface wherein the first endof the contact tip extends into the indention in the second end of theinsert so that the radiused end surface of the contact tip abuts theradiused inner surface of the insert and a surface of contact betweenthe insert and the contact tip is increased to increase the cooling ofthe contact tip. In one embodiment, the gas is controlled by selecting aposition of the hole in the wall of the insert so that the hole in thewall of the insert is axially misaligned with the hole in the wall ofthe diffuser sleeve. In one embodiment, the chamber has opposed firstand second ends having an axial length therebetween and the gas iscontrolled by varying a diameter of the chamber along the axial lengthof the chamber. In one embodiment, the gas is controlled by changing asize of the hole in the wall of the insert. In one embodiment, the gasis controlled by changing a size of the hole in the wall of the diffusersleeve. In one embodiment, the gas is controlled by selecting a size ofthe hole in the wall of the insert and selecting a size of a hole in thediffuser sleeve so that the size of the hole in the wall of the insertis not equal to the size of the hole in the diffuser sleeve. In oneembodiment, the gas is controlled by selecting the size of the hole inthe wall of the insert so that the size of the hole in the wall of theinsert is less than the size of the hole in the wall of the diffusersleeve. In one embodiment, the gas is controlled by changing a positionof the hole in the wall of the insert. In one embodiment, the gas iscontrolled by changing a position of the hole in the wall of thediffuser sleeve. In one embodiment, the gas is controlled by providingmore than one hole in the insert. In one embodiment, the gas iscontrolled by providing more than one hole in the diffuser sleeve. Inone embodiment, the diffuser has a first and second end and the secondend of the diffuser has an indention with a radiused inner surface andthe contact tip has a first and second end, the first end having aradiused end surface, the first end of the contact tip extends into theindention in the second end of the diffuser so that the radiused endsurface of the contact tip abuts the radiused inner surface of thediffuser and a surface of contact between the diffuser and the contacttip is increased to increase cooling of the contact tip. In oneembodiment, the gas is controlled by selecting a position of the hole inthe wall of the diffuser so that the hole in the wall of the insert isaxially misaligned with the hole in the wall of the diffuser sleeve. Inone embodiment, the chamber has opposed first and second ends having anaxial length therebetween and the gas is controlled by varying adiameter of the chamber along the axial length of the chamber. In oneembodiment, the gas is controlled by selecting a size of the hole in thewall of the diffuser and selecting a size of a hole in the diffusersleeve so that the size of the hole in the wall of the diffuser is notequal to the size of the hole in the diffuser sleeve. In one embodiment,the gas is controlled by selecting the size of the hole in the wall ofthe diffuser so that the size of the hole in the wall of the diffuser isless than the size of the hole in the wall of the diffuser sleeve. Inone embodiment, the gas is controlled by changing a position of the holein the wall of the diffuser. In one embodiment, the gas is controlled byproviding more than one hole in the diffuser.

The substance and advantages of the present invention will becomeincreasingly apparent by reference to the following drawings and thedescription.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross section view of one embodiment of the end assembly 10showing the gooseneck 12, the diffuser sleeve 20, the insert 40, thechamber 50, the contact tip 32 and the nozzle 36.

FIG. 2 is a side view of one embodiment of the end assembly 10 withoutthe nozzle 36 showing the gooseneck 12, the diffuser sleeve 20 and thecontact tip 32.

FIG. 3 is a cross section view of the end assembly 10 of FIG. 2 alongthe line 3-3 showing the chamber 50 between the diffuser sleeve 20 andinsert 40.

FIG. 4 is a exploded view of the end assembly 10 of FIG. 2 .

FIG. 5 is a side view of one embodiment of the contact tip 32 showingthe radiused first end 32D and the buttress threads 32C adjacent theradiused second end 32D.

FIG. 6 is a is a side view of one embodiment of the insert 40.

FIG. 7 is a perspective view of one embodiment of the insert 40

FIG. 8 is a side view of another embodiment of the insert 48.

FIG. 9 is a perspective view of the embodiment of the insert 48.

FIG. 10 is a cross section view of another embodiment of the endassembly 10 without the nozzle 36 showing the second end 12B of thegooseneck 12, the diffuser sleeve 20, the insert 49 and the contact tip32.

FIG. 11 is a cross section view of a second embodiment showing thegooseneck 212, the diffuser sleeve 220, the contact tip 232 and thenozzle 236 and showing the diffuser 240 not in cross section.

FIG. 12 is a cross section view of one embodiment of an end assembly 10showing the flow of gas 118.

FIG. 13 is a schematic view of a welding system 100 showing the weldingdevice 110 connected to the gas supply 102, the electrode supply 104 andpower supply 106.

FIG. 14 is a cross section view of a third embodiment showing thediffuser sleeve 321, the insert 340 and the contact tip 332.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 13 is a general, schematic representation of a MIG welding system100. The welding system 100 includes a gas supply 102, an electrodesupply 104, and a power supply 106 connected to a welding device 110. Ingeneral the welding device 110 includes a handle 112, a gooseneck 12 or212 and an end assembly 10, 210 or 310. The welding system 100 alsoincludes an activation switch which, in one embodiment, is a trigger 114on the handle 112 of the welding device 110. It is understood that thewelding system 100 can be activated similar to any welding system wellknown in the art. FIG. 1 shows one embodiment of the first embodiment ofthe end assembly 10 of the present invention having a gooseneck 12, adiffuser sleeve 20, an insert 40, a contact tip 32 and a nozzle 36. FIG.11 shows one embodiment of an alternative embodiment of the end assembly210 of the present invention having a gooseneck 212, a diffuser 240, adiffuser sleeve 220, a contact tip 232 and a nozzle 236. FIG. 14 showsanother embodiment of the end assembly 310 of the present inventionhaving a gooseneck (not shown), a diffuser sleeve 321, an insert 340, acontact tip 332 and a nozzle 336.

In the first embodiment of the present invention, the gooseneck 12 hasopposed first and second ends 12A and 12B with a passageway 14 extendingtherebetween. The first end 12A of the gooseneck 12 is connected to thehandle 112 of the welding device 110. The gooseneck 12 includes an innerconduit 16 which extends between the ends 12A and 12B and forms thepassageway 14. The inner conduit 16 is constructed of a conductivematerial. In one embodiment, the inner conduit 16 is constructed ofcopper. In one embodiment, the inner conduit 16 is a flexible cablehaving a center bore. The gooseneck 12 also includes an outer housing 18or covering which protects the inner conduit 16. The passageway 14 ofthe gooseneck 12 is sized to enable the electrode 116 and gas 118 tomove through the passageway 14 from the first end 12A to the second end12B of the gooseneck 12. In one embodiment, the gooseneck 12 is similarto a gooseneck well known in the art.

The diffuser sleeve 20 has opposed first and second ends 20A and 20Bwith a wall 28 therebetween forming an inner cavity 22 extendingtherebetween along a longitudinal axis A-A of the diffuser sleeve 20.The first end 20A of the diffuser sleeve 20 is mounted on the second end12B of the gooseneck 12. The inner cavity 22 extends between the openfirst end 20A and the open second end 20B. The size and shape of theinner cavity 22 of the diffuser sleeve 20 varies depending on the typeof gooseneck 12, the size of the insert 40 and the type of contact tip32 used in the end assembly 10. In one embodiment, the inner cavity 22at the first end 22A has an essentially cylindrical shape to connect tothe essentially cylindrical shaped second end 12B of the gooseneck 12.In one embodiment, the inner cavity 22 adjacent the first end 20A of thediffuser sleeve 20 has threads and the outer surface of the second end12B of the gooseneck 12 has threads and the diffuser sleeve 20 isthreadably connected to the second end 12B of the gooseneck 12. In oneembodiment, the second end 12B of the gooseneck 12 is press fit into theinner cavity 22 of the diffuser sleeve 20 at the first end 20A. It isunderstood that the diffuser sleeve 20 can be secured on the second end12B of the gooseneck 12 by any means well known in the art. The diffusersleeve 20 includes a first portion 24 adjacent the first end 20A and asecond portion 26 adjacent the second end 20B. In one embodiment, thediameter of the second portion 26 of the diffuser sleeve 20 is less thanthe diameter of the first portion 24 of the diffuser sleeve 20. The wall28 has a first end 28A adjacent the first portion 24 of the diffusersleeve 20 and a second end 28B adjacent the second portion 26 of thediffuser sleeve 20 with an inner surface 28C and an outer surface 28Dextending between the ends 28A and 28B with a length between the ends28A and 28B extending along the longitudinal axis A-A of the diffusersleeve 20. In one embodiment, an inner surface 28C of the wall 28 istapered. In one embodiment, a thickness of the wall 28 along the lengthof the diffuser sleeve 20 is constant. In one embodiment, the thicknessof the wall 28 varies along the length. In one embodiment, the innercavity 22 along the length of the wall 28 has a cylindrical shape. Inone embodiment, the wall 28 is tapered such that the thickness of thewall 28 increases along the length of the wall 28 from the first end 28Aadjacent the first portion 26 to the second end 28B adjacent the secondportion 28 of the diffuser sleeve 20. The wall 28 has a least on hole30. In one embodiment, the wall 28 has a plurality of holes 30 spacedaround the perimeter of the wall 28. The holes 30 in the wall 28 are influid communication with the inner cavity 22. In one embodiment, theholes 30 are evenly spaced around the perimeter of the wall 28. In oneembodiment, the wall 28 has a cylindrical shape along the length and theholes 30 are spaced around a circumference of the wall 28 along a commonplane perpendicular to the longitudinal axis A-A of the diffuser sleeve20. In one embodiment, the wall 28 has more than one hole 30 anddifferent holes 30 are located at different positions along the lengthof the wall 28 and are spaced around a circumference of the wall 28 suchthat the holes 30 are located in more than one plane perpendicular tothe longitudinal axis A-A of the diffuser sleeve 20. In one embodiment,the inner cavity 22 adjacent the wall 28 has an essentially cylindricalshape. In one embodiment, the outer surface of the first portion 26 ofthe diffuser sleeve 20 is provided with threads for mounting the nozzle36 on the diffuser sleeve 20. In one embodiment the outer surface offirst portion 26 of the diffuser sleeve 20 is provided with grippingflats for gripping the diffuser sleeve 20 to secure the diffuser sleeve20 onto the gooseneck 12. The interior surface of the inner cavity 22adjacent the second end 20B of the diffuser sleeve 20 has threads 31. Inone embodiment, the threads 31 are buttress threads. In one embodiment,the diffuser sleeve 20 is constructed of a poorly conductive ornonconductive material or of a material less conductive than thematerial used to construct the insert 40 and the contact tip 32. In oneembodiment, the diffuser sleeve 20 is constructed of a materialdissimilar to the material used to construct the insert 40 and thecontact tip 32. In one embodiment, the diffuser sleeve 20 is constructedof brass. In one embodiment, the diffuser sleeve 20 is constructed of360 half hard brass. In one embodiment, the diffuser sleeve 20 isconstructed of ceramic. In one embodiment, the diffuser sleeve 20 isconstructed of a high temperature polymer. In one embodiment, thediffuser sleeve 20 is constructed of a ferrous material. In oneembodiment, the diffuser sleeve 20 is constructed of a non-ferrousmaterial. The contact tip 32 has a first end 32A and a second end 32Bwith a center bore 34 extending therebetween. The first end 32B of thecontact tip 32 is connected to the second end 20B of the diffuser sleeve20. The first end 32A of the contact tip 32 extends into the innercavity 22 of the diffuser sleeve 20 at the second end 20B of thediffuser sleeve 20. The center bore 34 of the contact tip 32 extendsalong the longitudinal axis of the contact tip 32. When the contact tip32 is secured in the second end 20B of the diffuser sleeve 20, thecenter bore 34 of the contact tip 32 is coaxial with the longitudinalaxis A-A of the diffuser sleeve 20. In one embodiment, the first end 32Aof the contact tip 32 has threads 32C which mate with threads 31 on theinterior surface of the inner cavity 22 of the diffuser sleeve 20. Inone embodiment, the threads 32C of the contact tip 32 are buttressthreads. In one embodiment, the contact tip 32 has four (4) threads. Inone embodiment, the buttress threads are American National StandardsInstitute 45/7 or ANSI 45/7 buttress threads. In one embodiment, thebuttress threads are 5/16 - 20 buttress threads with a 0.304 inch (7.72mm) diameter major and a 0.326 inch (8.28 mm) +/- 0.002 inch (0.051 mm)pitch diameter using 0.029 inch (0.737 mm) diameter pins. In oneembodiment, the pitch of the threads 32C is at a 60 degree angle and thethreads 32C have a diameter of 0.312 inches (7.92 mm). In oneembodiment, the first end 32A of the contact tip 32 has a radiused outerend surface 32D. In one embodiment, the first end 32A of the contact tip32 is elongated with the threads 32C spaced apart from the first end 32Aof the contact tip 32. In one embodiment, the second end 32B of thecontact tip 32 is radiused or rounded or curved. In one embodiment, thefirst end 32A of the contact tip 32 has a first section and a secondsection (FIG. 5 ). The first section is located adjacent the first end32A of the contact tip 32 and the second section is spaced between thefirst section and the threads 32C. In one embodiment, the first andsecond sections are tapered. In one embodiment, a diameter of the secondsection adjacent the threads 32C is greater than a diameter of thesecond section adjacent the first section. In one embodiment, the secondsection tapers from a diameter of about 0.257 inches (6.53 mm) adjacentthe threads 32C to a diameter of about 0.160 inches (4.064 mm) adjacentthe first section. In one embodiment, the radius of the second sectionis greater than the radius of the first section. In one embodiment, theradius of the first section is about 0.094 inches (2.38 mm) and theradius of the second section is about 0.375 inches (9.53 mm). In oneembodiment, the second end 32B of the contact tip 32 has a first sectionand a second section. The second section is adjacent the second end 32Bof the contact tip 32 and the first section is spaced between the secondsection and the body of the contact tip 32. The first section of thesecond end 32B of the contact tip 32 is tapered so that the portion ofthe first section adjacent the first end 32A of the contact tip 32 has adiameter greater than the portion of the first section adjacent thesecond end 32B of the contact tip 32. In one embodiment, the firstsection of the second end 32B of the contact tip 32 tapers from adiameter of about 0.351 inches (8.42 mm) adjacent the first end 32A to adiameter of about 0.303 inches (7.70 mm) adjacent the second section andthe second end 32B of the contact tip 32. In one embodiment, the secondsection of the second end 32B of the contact tip 32 is radiused. In oneembodiment, the second section of the second end 32B of the contact tip32 has a radius of about 0.125 inches (3.18 mm). In one embodiment, thecontact tip 32 has a length between the ends 32A and 32B of essentially1.492 inches (37.89 mm). In one embodiment, the second section of thefirst end 32A of the contact tip 32 is spaced about 0.037 inches (0.93mm) from the first end 32A of the contact tip 32 and has a length ofabout.126 inches (3.20 mm). In one embodiment, the threads 32C areimmediately adjacent the second section of the first end 32A of thecontact tip 32. In one embodiment, the first section of the second end32B of the contact tip 32 is spaced about 1.132 inches (28.74 mm) fromthe first end 32A of the contact tip 32 and has a length of about 0.251inches (6.375 mm). In one embodiment, the second section of the secondend 32B of the contact tip 32 has a length of about 0.109 inches (2.76mm). In one embodiment, the second section of the second end 32B of thecontact tip 32 has a radius of about 0.125 inches (3.18 mm). In oneembodiment, the contact tip 32 has a band formed by grooves in the outersurface of the contact tip 32 spaced between the first and second ends32A and 32B adjacent the first section of the second end 32B. In oneembodiment, the band has a length along the length of the contact tip 32of essentially 0.030 inches (0.75 mm). In one embodiment, the contacttip 32 is constructed of conductive material. In one embodiment, thecontact tip 32 is constructed of copper. In one embodiment, the contacttip 32 is constructed of tempered copper. In one embodiment, the contacttip 32 is constructed of deoxidized high phosphorous copper (DHP) 122.

The nozzle 36 has a first end 36A and an open second end 36B with a gaschannel 38 extending therebetween. The first end 36A of the nozzle 36 isconnected to the first portion 24 of the diffuser sleeve 20. When thenozzle 36 is secured on the diffuser sleeve 20, the nozzle 36 extendsoutward from the first end 36A along the diffuser sleeve 20 toward thesecond end 36B and toward the second portion 26 of the diffuser sleeve20 so that the wall 28 of the diffuser sleeve 20 is in the gas channel38 and the hole 30 in the wall 28 of the diffuser sleeve 20 is in fluidcommunication with the gas channel 38 of the nozzle 36. The nozzle 36extends along the contact tip 32 so that the contact tip 32 is in thegas channel 38. In one embodiment, the second end 38B of the nozzle 38extends beyond the second end 32B of the contact tip 32. In oneembodiment, the second end 38B of the nozzle 38 is essentially even withthe second end 32B of the contact tip 32. In one embodiment, the secondend 32B of the contact tip 32 extends beyond the second end 36B of thenozzle 36. In one embodiment, the end of the gas channel 38 adjacent thesecond end 32B of the contact tip 32 is tapered inward toward thecontact tip 32. The nozzle 36 is similar to nozzles well known in theart.

The insert 40 has a first end 40A and a second end 40B with innerpassageway 46 extending therebetween. The insert 40 has a first partadjacent the first end 40A and a second part adjacent the second end 40Bwith a wall 42 extending therebetween. The insert 40 can have a varietyof shapes and sizes. The shape of the insert 40 can vary depending onthe shape and size of the inner cavity 22 of the diffuser sleeve 20, theshape and size of the second end 12B of the gooseneck 12 and the shapeand size of the contact tip 32. The shape and size of the insert 40 canvary depending on the specific use of the welding device 110. In oneembodiment, the first part of the insert 40 is cylindrical to enable thesecond end 12B of the gooseneck 12 to abut against the first end 40A ofthe insert 40 to secure the insert 40 in position in the diffuser sleeve20 (FIG. 1 ). In one embodiment, the first part of the insert 48 has acylindrical, open first end 48A and the second end 12B of the gooseneck12 is inserted into the first end 48A of the insert 48 to secure theinsert 40 in position in the diffuser sleeve 20 (FIGS. 8 and 9 ). Inanother embodiment, the insert 48 has an elongated first part with anexterior shoulder spaced apart from the first end. In this embodiment,the elongated first part of the insert 49 extends into the passageway 14of the gooseneck 12 and the second end 12B of the gooseneck 12 contactsthe shoulder to secure the insert 49 in position in the diffuser sleeve20 (FIG. 10 ).

The wall 42 of the insert 40 has a first end 42A adjacent the first partof the insert 40 and a second end 42B adjacent the second part of theinsert 40 with an inner surface and an outer surface 42D extendingbetween the ends 42A and 42B. The wall 42 has a length between the ends42A and 42B extending along the longitudinal axis of the insert 40. Inone embodiment, a thickness of the wall 42 along the length of theinsert 40 is constant. In one embodiment, the thickness of the wall 42varies along the length. In one embodiment, the wall 42 is tapered suchthat the thickness of the wall 42 increases along the length of the wall42 adjacent the first part to adjacent the second part of the insert 40.In one embodiment, the outer surface 42D of the wall 42 is angled. Thewall 42 has at least one hole 44 extending therethrough. In oneembodiment, the wall 42 has a plurality of holes 44. In one embodiment,the wall 42 has a cylindrical shape and the holes 44 are spaced apartaround a perimeter of the wall 42 of the insert 40. In one embodiment,the holes 44 are evenly spaced around the perimeter of the wall. In oneembodiment, the wall 42 has a cylindrical shape along the length and theholes 44 are spaced around a circumference of the wall 42 along a commonplane perpendicular to the longitudinal axis of the insert 40. In oneembodiment, the insert 40 has more than one hole and different holes 44are located at different positions along the length of the insert 40around a circumference of the wall 42 such that the holes 44 are in morethan one plane perpendicular to the longitudinal axis of the insert 40.In one embodiment, the inner passageway 46 of the insert 40 extendingalong the length of the wall 42 has a cylindrical shape. The holes 44 inthe wall 42 are in fluid communication with the inner passageway 46 ofthe insert 40.

The inner passageway 46 of the insert 40 has a first section 46A, adiffuser section 46B and a second section 46C. The first section 46A isadjacent the open, first end 40A of the insert 40. The first section 46Aof the inner passageway 46 is adjacent the second end 12B of thegooseneck 12 and in direct communication with the passageway 14 of thegooseneck 12. The shape and size of the first section 46A of the innerpassageway 46 can vary depending on the shape and size of the second end12B of gooseneck 12. The first section 46A of the inner passageway 46 isin fluid communication with the diffuser section 46B of the innerpassageway 46. In one embodiment, the diameter of the first section 46Aof the inner passageway 46 is greater than or equal to the diameter ofthe diffuser section 46B so that the gas 118 flows from the passageway14 of the gooseneck 12 into the first section 46A of the innerpassageway 46 and into the diffuser section 46B of the inner passageway46 of the insert 40. In one embodiment, the wall 42 of the insert 40extends beyond the diffuser section 46B of the inner passageway 46 tothe second section 46C of the inner passageway 46. In one embodiment,the diffuser section 46B has an essentially cylindrical shape. In oneembodiment, the size of diffuser section 46B decreases in a directiontoward the second section 46C of the inner passageway 46. The diameterof the second section 46C of the inner passageway 46 is less than adiameter of the diffuser section 46B. The diameter of the second section46C is greater than a diameter of the electrode 116 so that theelectrode 116 can extend through the second section 46C into the centerbore 34 of the contact tip 32. The second section 46C of the innerpassageway 46 of the insert 40 at the second end 40B is coaxial with thecenter bore 34 of the contact tip 32 to enable the electrode 116 to movesmoothly through the inner passageway 46 of the insert 40 into thecenter bore 34 of the contact tip 32. In one embodiment, the second end40B of the insert 40 has an indention 40C with an inner surface 40D. Inone embodiment, the indention 40C is radiused having a radiused innersurface 40D. In one embodiment, the inner surface 40D is radiusedsimilar to the first end 32A of the contact tip 32. In one embodiment,the indention 40C has a first section spaced apart from the first end40A of the insert 40 and a second section spaced adjacent the second end40B of the insert 40. In one embodiment, the radii of the inner surfaces40B of the first and second sections of the indention 40C correspond andmatch the radii of the outer surfaces of the first and second sectionsof the first end 32A of the contact tip 32. The first section of theindention 40C has a concave radiused inner surface which matches theconvex outer surface of the first section of the first end 32A of thecontact tip 32. In one embodiment, the inside contour of the firstsection of the indention 40C has a radius of about 0.094 inches (2.38mm) and the second section of the indention 40C has an inside contour ofabout 0.375 inches (9.53 mm). In one embodiment, the length of theindention 40C is essentially equal to the length of the first and secondsections of the first end 32A of the contact tip 32. In one embodiment,the length of the first section of the indention 40C is essentiallyequal to the length of the first section of the first end 32A of thecontact tip 32 and the length of the second section of the indention 40Cis essentially equal to the length of the second section of the firstend 32A of the contact tip 32. In one embodiment, the insert 40 isconstructed of a conductive material. In one embodiment, the insert 40is constructed of copper. In one embodiment, the insert 40 isconstructed of tempered copper. In one embodiment, the insert 40 isconstructed of C110 copper.

The insert 40 is positioned in the inner cavity 22 of the diffusersleeve 20 axially spaced between the contact tip 32 and second end 12Bof the gooseneck 12. When the insert 40 is secured in the diffusersleeve 20, the insert 40 is coaxial with the diffuser sleeve 20. Theinsert 40 is positioned in the inner cavity 22 of the diffuser sleeve 20so that the wall 42 of the insert 40 is axially adjacent or essentiallyat the same position along the longitudinal axis A-A of the diffusersleeve or the longitudinal axis of the end assembly 10 as the wall 28 ofthe diffuser sleeve 20. The outer surface 42D of the wall 42 of theinsert 40 is spaced apart from the inner surface 28C of the wall 28 ofthe diffuser sleeve 20 forming a chamber 50 positioned between the wall42 of the insert 40 and the wall 28 of the diffuser sleeve 20. Thechamber 50 has a length extending along the longitudinal axis of the endassembly 10. In one embodiment, the outer surface 42D of the wall 42 ofthe insert 40 is angled along an axial length and the chamber 50 alongthe length is tapered. In one embodiment, the inner surface 28D of thewall 28 of the diffuser sleeve 20 is angled along an axial length andthe chamber 50 is tapered along the length. In one embodiment, thelength of the wall 42 of the insert 40 is varied to change the length ofthe chamber 50. In one embodiment, the length of the wall 28 of thediffuser sleeve 20 is varied to change the length of the chamber 50. Inone embodiment, the length of the wall 42 of the insert 40 is not equalto the length of the wall 28 of the diffuser sleeve 20. In oneembodiment, a shape of the outer surface 42D of the wall 42 of theinsert 40 is varied to change or adjust the shape and size of thechamber 50. In one embodiment, the inner surface 28C of the wall 28 ofthe diffuser sleeve 20 is varied to change the size and shape of thechamber 50. In one embodiment, the diameter of the chamber 50 adjacentthe first end 40A of the insert 40 is less than the diameter of thechamber 50 adjacent the second end 40B of the insert 40. The holes 44 inthe wall 42 of the insert 40 and the holes 30 in the wall 28 of thediffuser sleeve 20 are in fluid communication with the chamber 50. Inone embodiment, the holes 44 in the wall 42 of the insert 40 areperpendicular to the longitudinal axis of the insert 40. In oneembodiment, the holes 44 in the wall 42 of the insert 40 are angled withrespect to the longitudinal axis of the insert 40. In one embodiment,the holes 30 in the wall 28 of the diffuser sleeve 20 are perpendicularto the longitudinal axis A-A of the diffuser sleeve 20. In oneembodiment, the holes 30 in the wall 28 of the diffuser sleeve 20 areangled with respect to the longitudinal axis A-A of the diffuser sleeve20. In one embodiment, when the insert 40 is positioned in the diffusersleeve 20, the holes 44 in the wall 42 of the insert 40 are not axiallyaligned or are axially misaligned or offset from the holes 30 in thewall 28 of the diffuser sleeve 20. In one embodiment, when the insert 40is positioned in the diffuser sleeve 20, the holes 44 in the wall 42 ofthe insert 40 and the holes 30 in the wall 28 of the diffuser sleeve 20are not in the same plane perpendicular to the longitudinal axis of theend assembly 10. In one embodiment, when the insert 40 is positioned inthe diffuser sleeve 20, the holes 44 in the wall 42 of the insert 40 areaxially spaced apart from the holes 30 in the wall 28 of the diffusersleeve 20. In one embodiment, when the insert 40 is positioned in thediffuser sleeve 20, the holes 44 in the wall 42 of the insert 40 areaxially positioned between the first end 20A of the diffuser sleeve 20and the holes 30 in the wall 28 of the diffuser sleeve 20. In anotherembodiment, when the insert 40 is positioned in the diffuser sleeve 20,the holes 30 in the diffuser sleeve 20 are axially positioned betweenthe first end 20A of the diffuser sleeve 20 and the holes 44 in the wall42 of the insert 40. In one embodiment, the diameter of the holes 30 inthe wall 28 of the diffuser sleeve 20 is greater than the diameter ofthe holes 44 in the wall 42 of the insert 40. In one embodiment, thediameter of the holes 30 in the wall 28 of the diffuser sleeve 20 isless than the diameter of the holes 44 in the wall 42 of the insert 40.In one embodiment, the diameter of the holes 30 in the wall 28 of thediffuser sleeve 20 is essentially equal to the diameter of the holes 44in the wall 42 of the insert 40. In one embodiment, the number of holes30 in the wall 28 of the diffuser sleeve 29 is equal to the number ofholes 42 on the wall 42 of the insert 40. In one embodiment, the numberof holes 30 in the wall 28 of the diffuser sleeve 20 is less than thenumber of holes 44 in the wall 42 of the insert 40. In one embodiment,the number of holes 30 in the wall 28 of the diffuser sleeve 20 isgreater than the number of holes 44 in wall 42 of the insert 40. It isunderstood that the number and diameter of the holes 30 in the wall 28of the diffuser sleeve 20 and number and diameter of the holes 44 in thewall 42 of the insert 40 can vary depending of the use of the weldingdevice 110, the type of gas 118 used during welding, the material usedto construct the contact tip 32, the material used to construct theinsert 40 and the amount of current used during welding as well as othervariables.

In the second embodiment of the present invention, the gooseneck 212 hasa first end 212A and a second end 212B with an inner conduit 216extending between the ends 212A and 212B forming the passageway 214. Inone embodiment the gooseneck 212 is flexible and the inner conduit 216is a flexible cable. The inner conduit 216 is constructed of aconductive material. In one embodiment, the inner conduit 216 isconstructed of copper. The diffuser 240 is connected to the second end212B of the gooseneck 212. In one embodiment, the diffuser 240 isseparate but in contact with the inner conduit 216 at the second end212B of the gooseneck 212. In one embodiment, the diffuser 240 isthreadably connected to the second end 212B of the gooseneck 212. In oneembodiment, the diffuser 240 is an integral part of the inner conduit216 at the second end 212B of the gooseneck 212. In one embodiment, thediffuser 240 is constructed of the same material as the inner conduit216. In one embodiment, the diffuser 240 is constructed of a conductivematerial. In one embodiment, the diffuser 240 is constructed of copper.In one embodiment, the diffuser 240 is constructed of tempered copper.

The diffuser 240 has a first end 240A and a second end 240B with innerpassageway 246 and a wall 242 extending therebetween. The first end 240Aof the diffuser 240 is connected to the second end 212B of the gooseneck212. The diffuser 240 can have a variety of shapes and sizes. The shapeof the diffuser 240 can vary depending on the shape and size of theinner cavity 222 of the diffuser sleeve 220, the shape and size of thesecond end 212B of the gooseneck 212 and the shape and size of thecontact tip 232. The shape and size of the diffuser 240 can varydepending on the specific use of the welding device 110. The wall 242has a first end 242A adjacent gooseneck 212 and an opposed second end242B with an inner surface and an outer surface 242D extending betweenthe ends 242A and 242B. The wall 242 has a length between the ends 242Aand 242B extending along the longitudinal axis of the diffuser 240. Inone embodiment, a thickness of the wall 242 along the length of thediffuser 240 is constant. In one embodiment, the thickness of the wall242 varies along the length. In one embodiment, the wall 242 is taperedsuch that the thickness of the wall 242 decreases along the length ofthe wall 242 from adjacent the first end 240A to adjacent the second end204B of the diffuser 240. In one embodiment, the outer surface of thewall 242 is angled. The wall 242 has at least one hole 244 extendingtherethrough. The hole 244 is in fluid communication with the innerpassageway 246 of the diffuser 240. In one embodiment, the wall 242 hasa plurality of holes 244. In one embodiment, the wall 242 has acylindrical shape and the holes 244 are spaced apart around a perimeterof the wall 242 of the diffuser 240. In one embodiment, the holes 244are evenly spaced around the perimeter of the wall 242. In oneembodiment, the wall 242 has a cylindrical shape along the length andthe holes 244 are spaced around a circumference of the wall 242 along acommon plane perpendicular to the longitudinal axis of the diffuser 240.In one embodiment, the diffuser 240 has more than one hole 244 anddifferent holes 244 are located at different positions along the lengthof the diffuser 240 and are spaced around a circumference of the wall242 such that the holes 244 are in more than one plane perpendicular tothe longitudinal axis of the diffuser 240.

The inner passageway 246 of the diffuser 240 has a first, diffusersection 246A adjacent the first end 240A and a second section 246Badjacent the second end 240B of the diffuser 240. The first, diffusersection 246A of the inner passageway 246 is adjacent the second end 212Bof the gooseneck 212 and in direct communication with the passageway 214of the gooseneck 212. The shape and size of the first diffuser section246A of the inner passageway 246 can vary depending on the shape andsize of the second end 212B of gooseneck 212. In one embodiment, thefirst diffuser section 246A of the inner passageway 246 of the diffuser240 extends along the length of the wall 242 and has a cylindricalshape. In one embodiment, the diameter of the first diffuser section246A of the inner passageway 246 is greater than the diameter of thesecond section 246B of the inner passageway 246. In one embodiment, thesize of diffuser section 246A decreases in a direction toward the secondsection 246B of the diffuser 240. The diameter of the second section246B is greater than a diameter of the electrode 116 so that theelectrode 116 can extend through the second section 246B into the centerbore 234 of the contact tip 232. The second section 246B of the innerpassageway 246 of the diffuser 240 at the second end 240B is coaxialwith the center bore 234 of the contact tip 232 to enable the electrode116 to move smoothly through the inner passageway 246 of the diffuser240 into the center bore 234 of the contact tip 232.

The diffuser sleeve 220 of the second embodiment is similar to thediffuser sleeve 20 of the first embodiment. The diffuser sleeve 220 hasopposed first and second ends 220A and 220B with an inner cavity 222extending therebetween along a longitudinal axis A′-A′ of the diffusersleeve 220. The diffuser sleeve 220 has a first portion 224 adjacent thefirst end 220A and a second portion 226 adjacent the second end 220Bwith a wall 228 extending between the first portion 226 and the secondportion 228. In one embodiment, the diameter of the second portion 226of the diffuser sleeve 220 is less than the diameter of the firstportion 224 of the diffuser sleeve 220. The wall 228 has a first end228A adjacent the first portion 224 of the diffuser sleeve 220 and asecond end 228B adjacent the second portion 226 of the diffuser sleeve220 with an inner surface 228C and an outer surface 228D extendingbetween the ends 228A and 228B with a length between the ends 228A and228B extending along the longitudinal axis A′-A′ of the diffuser sleeve220. In one embodiment, an inner surface 228C of the wall 228 istapered. In one embodiment, a thickness of the wall 228 along the lengthof the diffuser sleeve 220 is constant. In one embodiment, the thicknessof the wall 228 varies along the length. In one embodiment, the innercavity 222 along the length of the wall 228 has a cylindrical shape. Inone embodiment, the wall 228 is tapered such that the thickness of thewall 228 increases along the length of the wall 228 from the first end228A adjacent the first portion 224 to the second end 228B adjacent thesecond portion 226 of the diffuser sleeve 220. The wall 228 has a leastone hole 230. In one embodiment, the wall 228 has a plurality of holes230 spaced around the perimeter of the wall 228. The holes 230 in thewall 228 are in fluid communication with the inner cavity 222. In oneembodiment, the holes 230 are evenly spaced around the perimeter of thewall 228. In one embodiment, the wall 228 has a cylindrical shape alongthe length and the holes 230 are spaced around a circumference of thewall 228 along a common plane perpendicular to the longitudinal axisA′-A′ of the diffuser sleeve 220. In one embodiment, the wall 228 of thediffuser sleeve 220 has more than one hole 230 and different holes 230are located at different positions along the length of the diffusersleeve 220 and are spaced around a circumference of the wall 228 so thatthe holes are located in more than one plane perpendicular to thelongitudinal axis A′-A′ of the diffuser sleeve 220.

The diffuser sleeve 220 is secured on the second end 212B of thegooseneck 212 so that the second end 212B of the gooseneck 212 extendsinto the inner cavity 222 at the first end 220A of the diffuser sleeve220. It is understood that the diffuser sleeve 220 can be secured on thesecond end 212B of the gooseneck 212 by any means well known in the art.The diffuser sleeve 220 is positioned on the second end 212B of thegooseneck 212 so that the wall 228 of the diffuser sleeve 220 is axiallyadjacent the wall 242 of the diffuser 240 or essentially at the sameposition along the longitudinal axis A′-A′ of the diffuser sleeve 220 orthe longitudinal axis of the end assembly 210 as the wall 228 of thediffuser sleeve 220. When the diffuser sleeve 220 is secured on thegooseneck 212, the wall 228 of the diffuser sleeve 220 is spaced apartfrom the wall 242 of the diffuser 240 forming a chamber 250 positionedbetween the wall 228 of the diffuser sleeve 220 and the wall 242 of thediffuser 240. The outer surface 242D of the wall 242 of the diffuser 240is spaced apart from the inner surface 228C of the wall 228 of thediffuser sleeve 220 forming the chamber 250. In one embodiment, theouter surface 242D of the wall 242 of the diffuser 240 is angled alongan axial length so that the chamber 250 is tapered along the length. Inone embodiment, the length of the wall 242 of the diffuser 240 is variedto change the length of the chamber 250. In one embodiment, the lengthof the wall 228 of the diffuser sleeve 220 is varied to change thelength of the chamber 250. In one embodiment, the length of the wall 242of the diffuser 240 is not equal to the length of the wall 228 of thediffuser sleeve 220. In one embodiment, the shape of the outer surface242D of the wall 242 of the diffuser 240 is varied to change or adjustthe shape and size of the chamber 250. In one embodiment, the innersurface 228C of the wall 228 of the diffuser sleeve 220 is varied tochange a size and shape of the chamber 250. In one embodiment, thechamber 250 extends along the longitudinal axis A′-A′ of the diffusersleeve 220 and the diameter of the chamber 250 adjacent the first end240A of the diffuser 240 is less than the diameter of the chamber 250adjacent the second end 240B of the diffuser 240. The holes 244 in thewall 242 of the diffuser 240 and the holes 230 in the wall 228 of thediffuser sleeve 220 are in fluid communication with the chamber 250. Inone embodiment, the holes 244 in the wall 242 of the diffuser 240 areperpendicular to the longitudinal axis A′-A′ of the diffuser 240. In oneembodiment, the holes 244 in the wall 242 of the diffuser 240 are angledwith respect to the longitudinal axis A′-A′ of the diffuser 240. In oneembodiment, the diffuser 240 is positioned in the diffuser sleeve 220 sothat the holes 244 in the wall 242 of the diffuser 240 are not axiallyaligned or are axially misaligned of axially offset with the holes 230in the wall 228 of the diffuser sleeve 220. In one embodiment, when thediffuser 240 is positioned in the diffuser sleeve 220, the holes 244 inthe wall 242 of the diffuser 240 and the holes 230 in the wall 228 ofthe diffuser sleeve 220 are not in the same plane perpendicular to thelongitudinal axis of the end assembly 210. In one embodiment, when thediffuser 240 is positioned in the diffuser sleeve 220, the holes 244 inthe wall 242 of the diffuser 240 are axially spaced apart from the holes230 in the wall 228 of the diffuser sleeve 220. In one embodiment, whenthe diffuser 240 is positioned in the diffuser sleeve 220, the holes 244in the wall 242 of the diffuser 240 are axially positioned between thefirst end 220A of the diffuser sleeve 220 and the holes 230 in the wall228 of the diffuser sleeve 220. In another embodiment, when the diffuser240 is positioned in the diffuser sleeve 220, the holes 230 in the wall228 of the diffuser sleeve 220 are axially positioned between the firstend 220A of the diffuser sleeve 220 and the holes 244 in the wall 242 ofthe diffuser 240. In one embodiment, the diameter of the holes 230 inthe wall 228 of the diffuser sleeve 220 is greater than the diameter ofthe holes 244 in the wall 242 of the diffuser 240. In one embodiment,the diameter of the holes 230 in the wall 228 of the diffuser sleeve 220is less than the diameter of the holes 244 in the wall 242 of thediffuser 240. In one embodiment, the diameter of the holes 230 in thewall 228 of the diffuser sleeve 220 is essentially equal to the diameterof the holes 244 in the wall 242 of the diffuser 240. In one embodiment,the number of holes 230 in the wall 228 of the diffuser sleeve 220 isequal to the number of holes 244 in the diffuser 240. In one embodiment,the number of holes 230 in the wall 228 of the diffuser sleeve 220 isless than the number of holes 244 in the wall 242 of the diffuser 240.In one embodiment, the number of holes 230 in the wall 228 of thediffuser sleeve 220 is greater than the number of holes 244 in the wall242 of the diffuser 240. It is understood that the number and diameterof the holes 230 in the wall 228 of the diffuser sleeve 220 and numberand diameter of the holes 244 in the wall 242 of the diffuser 240 canvary depending of the use of the welding device 110, the type of gas 118used during welding, the material used to construct the contact tip 232,the material used to construct the diffuser 240 and the amount ofcurrent used during welding as well as other variables. In oneembodiment, the inner cavity 222 adjacent the wall 242 has anessentially cylindrical shape. In one embodiment, the diffuser sleeve220 is constructed of a poorly conductive or non-conductive material. Inone embodiment, the diffuser sleeve 220 is constructed of a materialwhich is less conductive than the material or materials used toconstruct the contact tip 232 or the diffuser 240. In one embodiment,the diffuser sleeve 220 is constructed of a material dissimilar to thematerial used to construct the contact tip 232 and diffuser 240. In oneembodiment, the diffuser sleeve 220 is constructed of brass. In oneembodiment, the diffuser sleeve 220 is constructed of 360 half hardbrass. In one embodiment, the diffuser sleeve 220 is constructed ofceramic. In one embodiment, the diffuser sleeve 220 is constructed of ahigh temperature polymer. In one embodiment, the diffuser sleeve 220 isconstructed of a ferrous material. In one embodiment, the diffusersleeve 220 is constructed of a non-ferrous material.

The contact tip 232 of the second embodiment is similar to the contacttip 32 of the first embodiment. The contact tip 232 is connected at thefirst end 232A to the second end 220B of the diffuser sleeve 220. Thecontact tip 232 can be secured to the diffuser sleeve 220 by any meanswell known in the art. In one embodiment of the second embodiment, thecontact tip 232 extends into the inner cavity 222 of the diffuser sleeve220 at the second end 220B of the diffuser sleeve 220. In oneembodiment, the first end 232A of the contact tip 232 has an indention232C having an inner surface 232D and the second end 240B of thediffuser 240 of the gooseneck 210 extends into the first end 232A of thecontact tip 232 (FIG. 11 ). The contact tip 232 is secured in contactwith the diffuser 240 of the gooseneck 210 by the diffuser sleeve 220.In one embodiment, the inner surface of the inner cavity 222 of thediffuser sleeve 220 at the second end 220B has threads which mate withthreads on the first end 232A of the contact tip 232. In one embodiment,the contact tip 232 is constructed of conductive material. In oneembodiment, the contact tip 232 is constructed of copper. In oneembodiment, the contact tip 232 is constructed of tempered copper. Inone embodiment, the contact tip 232 is constructed of deoxidized highphosphorous copper (DHP) 122.

The nozzle 236 has a first end 236A and an open second end 236B with agas channel 238 extending therebetween. The first end 236A of the nozzle236 is connected to the first portion 224 of the diffuser sleeve 220 byany means well known in the art. When the nozzle 236 is secured on thediffuser sleeve 220, the nozzle 236 extends outward from the first end236A along the diffuser sleeve 220 toward the second end 236B and towardthe second portion 226 of the diffuser sleeve 220 so that the wall 228of the diffuser sleeve 220 is in the gas channel 238 and the hole 230 inthe wall 228 of the diffuser sleeve 220 is in fluid communication withthe gas channel 238 of the nozzle 236. The nozzle 236 extends along thecontact tip 232 so that the contact tip 232 is in the gas channel 238.In one embodiment, the second end 238B of the nozzle 238 extends beyondthe second end 232B of the contact tip 232. In one embodiment, thesecond end 238B of the nozzle 238 is essentially even with the secondend 232B of the contact tip 232. In one embodiment, the second end 232Bof the contact tip 232 extends beyond the second end 236B of the nozzle236. In one embodiment, the second end 238B of the gas channel 238 istapered inward toward the contact tip 232. The nozzle 236 is similar tonozzles well known in the art.

In the third embodiment of the present invention, the end assembly 310includes a diffuser base 320 and a diffuser sleeve 321 (FIG. 14 ). Thediffuser base 320 has a first end 320A and a second end 320B with a wall327 extending therebetween surrounding and forming an inner cavity 320C.The first end 320A of the diffuser base 320 is connected to thegooseneck. The first end 320A of the diffuser base 320 mounts on thegooseneck so that the inner conduit of the gooseneck extends into thefirst end of the diffuser base 320 and into the inner cavity 320C of thediffuser base 320. The gooseneck (not shown) can be similar to anygooseneck well known in the art. The diffuser base 320 can be mounted onthe gooseneck by any means well known in the art. In one embodiment, theinner surface of the wall 327 forming and surrounding the inner cavity320C of the diffuser base 320 adjacent the first end 320A has firstthreads 320D and the diffuser base 320 is threadably connected to thegooseneck. In one embodiment, the inner surface of the wall 327 formingthe inner cavity 320C has second threads 320E. In one embodiment, thesecond threads 320E are spaced apart from the first end 320A and thesecond end 320B of the diffuser base 320. In one embodiment, the outersurface of the diffuser base 320 adjacent the second end 320B isprovided with third threads. In one embodiment, the diameter of thediffuser base 320 at the first end 320A is larger than the diameter ofthe diffuser base 320 at the second end 320B. However, it is understoodthat the shape of the diffuser base 320 can vary depending on the use ofthe end assembly 310.

The diffuser sleeve 321 is mounted adjacent the second end 320B of thediffuser base 320. The diffuser sleeve 321 has a first end 321A and asecond end 321B with a wall 328 extending therebetween forming an innerchamber between the ends 321A and 321B. The wall 328 extends between theends 321A and 321B along the longitudinal axis A″-A″ of the diffusersleeve 321. The wall 328 has an inner surface 328C and an outer surface328D extending between the ends 321A and 321B with a length between theends 321A and 321B extending essentially along the longitudinal axisA″-A″ of the diffuser sleeve 321. The wall 328 of the diffuser sleeve321 has a diffuser portion 328A spaced between the first and second ends321A and 321B of the diffuser sleeve 321. In one embodiment, thediffuser portion 328A is adjacent the second end 321B of the diffusersleeve 321. In one embodiment, the inner surface 328C of the wall 328adjacent the first end 321A is provided with first threads 328E. In oneembodiment, the inner surface 328C adjacent the second end 321B isprovided with second threads 328F. In one embodiment, the diffuserportion 328A is spaced apart from the second end 321B of the diffusersleeve 321 by the second threads 328F of the diffuser sleeve 321. In oneembodiment, the inner surface 328C of the diffuser portion 328A of thewall 328 is tapered. In one embodiment, a thickness of the diffuserportion 328A of the wall 328 along the length of the diffuser sleeve 321is constant. In one embodiment, the thickness of the diffuser portion328A of the wall 328 varies along the length. In one embodiment, theinner chamber along the length of the diffuser portion 328A of the wall328 has a cylindrical shape. In one embodiment, the diffuser portion328A of the wall 328 is tapered such that the thickness of the diffuserportion 328A of the wall 328 decreases along the length of the diffuserportion 328A of the wall 328 from the first end 321A of the diffusersleeve 321 toward the second end 321B of the diffuser sleeve 321. Thediffuser portion 328A of the wall 328 has a least one hole 330. In oneembodiment, the diffuser portion 328A of the wall 328 has a plurality ofholes 330 spaced around the outer surface 328D of the wall 328. Theholes 330 in the wall 328 are in fluid communication with the innerchamber of the diffuser sleeve 321. In one embodiment, the holes 330 areevenly spaced around the outer surface 328D of the wall 328. In oneembodiment, the diffuser portion 328A of the wall 328 has a cylindricalshape along the length of the diffuser sleeve 321 and the holes 330 arespaced around a circumference of the wall 328 along a common planeperpendicular to the longitudinal axis A″-A″ of the diffuser sleeve 321.In one embodiment, the diffuser portion 328A of the wall 328 has morethan one hole 330 and different holes 330 are located at differentpositions along the wall 328 of the diffuser portion 328A of thediffuser sleeve 321 and are spaced around a circumference of the wall328 such that the holes 330 are located in more than one planeperpendicular to the longitudinal axis A″-A″ of the diffuser sleeve 321.In one embodiment, the holes 330 are all essentially identical having asimilar size, shape and orientation. In one embodiment, the holes 330have different sizes. In one embodiment, the holes 330 have differentorientations. In one embodiment, the holes 330 have different shapes.

In one embodiment, the diffuser base 320 and the diffuser sleeve 321 areremoveably connected together. In one embodiment, the diffuser base 320and the diffuser sleeve 321 are connected together by the insert 340. Inone embodiment, the diffuser base 320 and the diffuser sleeve 321 are asingle piece. In one embodiment, the diffuser base 320 and the diffusersleeve 321 are constructed of the same material. In one embodiment, thediffuser base 320 and the diffuser sleeve 321 are constructed of brass.In one embodiment, the diffuser sleeve 321 is constructed of a materialdissimilar to the material used to construct the insert 340 and thecontact tip 332. In one embodiment, the diffuser base 320 is constructedof a material dissimilar to the material used to construct the insert340 and the contact tip 332. In one embodiment, the diffuser base 320and the diffuser sleeve 321 are not constructed of copper. In oneembodiment, the diffuser base 320 is constructed of a poorly conductiveor non-conductive material. In one embodiment, the diffuser base 320 isconstructed of a material that is less conductive than the material ormaterials used to construct the insert 340 or the contact tip 332. Inone embodiment, the diffuser base 320 is constructed of brass. In oneembodiment, the diffuser base 320 is constructed of 360 half hard brass.In one embodiment, the diffuser base 320 is constructed of ceramic. Inone embodiment, the diffuser base 320 is constructed of a hightemperature polymer. In one embodiment, the diffuser base 320 isconstructed of a ferrous material. In one embodiment, the diffuser base320 is constructed of a non-ferrous material. In one embodiment, thediffuser sleeve 321 is constructed of a poorly conductive ornon-conductive material. In one embodiment, the diffuser sleeve 321 isconstructed of a material that is less conductive than the material ormaterials used to construct the insert 340 or the contact tip 332.In oneembodiment, the diffuser sleeve 321 is constructed of brass. In oneembodiment, the diffuser sleeve 321 is constructed of 360 half hardbrass. In one embodiment, the diffuser sleeve 321 is constructed ofceramic. In one embodiment, the diffuser sleeve 321 is constructed of ahigh temperature polymer. In one embodiment, the diffuser sleeve 321 isconstructed of a ferrous material. In one embodiment, the diffusersleeve 321 is constructed of a non-ferrous material.

The insert 340 has a first end 340A and a second end 340B with a wall342 extending therebetween surrounding and forming an inner passageway346. The insert 340 can have a variety of shapes and sizes. The shape ofthe insert 340 can vary depending on the shape and size of the innercavity 320C of the diffuser base 320 and the inner chamber of thediffuser sleeve 321 and the shape and size of the contact tip 332. Theshape and size of the insert 340 can also vary depending on the specificuse of the welding device 110. The wall 342 of the insert 340 has aninner surface 342C and an outer surface 342D extending between the ends340A and 340B of the insert 340. The wall 342 has a length between theends 340A and 340B extending along the longitudinal axis of the insert340 which corresponds to the longitudinal axis A″-A″ of the diffusersleeve 321. In one embodiment, the outer surface 342D of the wall 342 ofthe insert 340 adjacent the first end 340A is provided with firstthreads 342E. In one embodiment, the outer surface 342D of the wall 342of the insert 340 spaced between first threads 342E and the second end340B of the insert 340 is provided with second threads 342F. In oneembodiment, a thickness of the wall 342 along the length of the insert340 is constant. The wall 342 of the insert 340 has a diffuser portion342A spaced between the first and second ends 340A and 340B of theinsert 340. In one embodiment, the thickness of the diffuser portion342A of the wall 342 varies along the length of the diffuser portion342A of the wall 342. In one embodiment, the diffuser portion 342A ofthe wall 342 is tapered such that the thickness of the wall 342decreases along the length of diffuser portion 342A the wall 342 fromthe first end 340A toward the second end 340B of the insert 340. In oneembodiment, the outer surface 342D of the diffuser portion 342A of thewall 342 is angled. In one embodiment, the diffuser portion 342A of thewall 342 is angled so that a size of the inner passageway 346 decreasesalong the length of the diffuser portion 342A from the first end 340Atoward the second end 340B of the insert 340. The diffuser portion 342Aof the wall 342 of the insert 340 has at least one hole 344 extendingthrough the wall 342. The hole 344 is in fluid communication with theinner passageway 346 of the insert 340. In one embodiment, the diffuserportion 342A of the wall 342 has a plurality of holes 344 extendingthrough the wall 342. In one embodiment, the diffuser portion 342A ofthe wall 342 has a cylindrical shape and the holes 344 are spaced apartaround the outer surface 342D of the diffuser portion 342A of the wall342. In one embodiment, the holes 344 in the diffuser portion 342A ofthe wall 342 of the insert 340 are essentially perpendicular to thelongitudinal axis of the insert 340. In one embodiment, the holes 344 inthe diffuser portion 342A of the wall 342 of the insert 340 are angledwith respect to the longitudinal axis of the insert 340. In oneembodiment, the holes 344 are evenly spaced around the diffuser portion342A of the wall 342 of the insert 340. In one embodiment, the diffuserportion 342A of the wall 342 has a cylindrical shape along the lengthand the holes 344 are spaced around a circumference of the diffuserportion 342A of the wall 342 along a common plane perpendicular to thelongitudinal axis of the insert 340. In one embodiment, the diffuserportion 342A of the wall 342 has more than one hole 344 and differentholes 344 are located at different positions along the length of thewall 342 of the diffuser portion 342A and are spaced around acircumference of the diffuser portion 342A of the wall 342 such that theholes 344 are in more than one plane perpendicular to the longitudinalaxis of the insert 340. In one embodiment, the holes 344 are essentiallyidentical having a similar size, shape and orientation. In oneembodiment, the holes 344 have different sizes. In one embodiment, theholes 344 have different orientations. In one embodiment, the holes 344have different shapes.

The inner passageway 346 of the insert 340 has a first section 346Aadjacent the first end 340A of the insert 340, a second section 346Cadjacent the second end 340B of the insert 340, and a diffuser section346B spaced between the first and second sections 346A and 346C. Thefirst section 346A of the inner passageway 346 of the insert 340 isdirectly adjacent and in direct communication with the passageway of thegooseneck. The shape and size of the first section 346A of the innerpassageway 346 can vary depending on the shape and size of the diffuserbase 320 and the passageway of the gooseneck. In one embodiment, thefirst section 346A of the inner passageway 346 of the insert 340 has acylindrical shape. In one embodiment, the diameter of the first section346A of the inner passageway 346 is greater than the diameter of thediffuser section 346B of the inner passageway 346. The diffuser section346B of the inner passageway 346 is adjacent the diffuser portion 342Aof the wall 342 of the insert 340. In one embodiment, the diffusersection 346B is tapered in a direction toward the second section 346C ofthe inner passageway 346 of the insert 340. The diameter of the secondsection 346C of the inner passageway 346 of the insert 340 is greaterthan a diameter of the electrode 116 so that the electrode 116 canextend through the second section 346C of the inner passageway 346 ofthe insert 340 and into the center bore 334 of the contact tip 332. Thesecond section 346C of the inner passageway 346 of the insert 340 at thesecond end 340B is coaxial with the center bore 334 of the contact tip332 to enable the electrode 116 to move smoothly through the innerpassageway 346 of the insert 340 into the center bore 334 of the contacttip 332. In one embodiment, an outer diameter of the second end 340B ofthe insert 340 is essentially equal to an outer diameter of the firstend 340A of the insert 340. In one embodiment, the second end 340B ofthe insert 340 has an indention 340C with an inner surface. In oneembodiment, the indention 340C is radiused having a radiused innersurface. In one embodiment, the shape of the indention 340C in thesecond end 340B of the insert 340 is essentially the exact opposite ofthe shape of the end surface 332D of the first end 332A of the contacttip 332 so that the first end 332A of the contact tip 332 sits securelyinto the indention 340C and the outer end surface 332D of the contacttip 332 fully contacts the radiused or curved inner surface of theindention 340C. In one embodiment, the insert 340 is constructed of aconductive material. In one embodiment, the insert 340 is constructed ofcopper. In one embodiment, the insert 340 is constructed of temperedcopper. In one embodiment, the insert 340 is constructed of C110 copper.

In one embodiment, the contact tip 332 of the third embodiment issimilar to the contact tip 32 of the first embodiment. The contact tip332 has a first end 332A and a second end 332B with a center bore 334extending the complete distance therebetween. The contact tip 332 isconnected at the first end 332A to the second end 321B of the diffusersleeve 321. The contact tip 332 can be secured to the diffuser sleeve321 by any means well known in the art. In one embodiment, the contacttip 332 extends into the inner chamber of the diffuser sleeve 321 at thesecond end 321B of the diffuser sleeve 321. In one embodiment, the firstend 332A of the contact tip 332 has threads which threadably mate withthe second threads 328F of the diffuser sleeve 321 and the contact tip332 is threadably secured to the diffuser sleeve 321. The contact tip332 is secured in the diffuser sleeve 321 so that the first end 332A ofthe contact tip 332 is in contact with the second end 340B of the insert340 so that the radiused outer end surface 332D of the contact tip 332is in tight contact with the radiused inner surface of the indention340C in the second end 340B of the insert 340. The contact tip 332 issecured in contact with the insert 340 by the diffuser sleeve 321. Inone embodiment, the contact tip 332 is constructed of conductivematerial. In one embodiment, the contact tip 332 is constructed ofcopper. In one embodiment, the contact tip 332 is constructed oftempered copper. In one embodiment, the contact tip 332 is constructedof deoxidized high phosphorous copper 122(DHP 122).

In one embodiment, a nozzle insulator 335 having a first end 335A andsecond end 335B with a center bore extending therebetween is mountedover the diffuser base 320 and the diffuser sleeve 321. In oneembodiment, the nozzle insulator 335 extends over both the second end320B of the diffuser base 320 and the first end 321A of the diffusersleeve 321 and covers the intersection of the diffuser base 320 and thediffuser sleeve 321. In one embodiment, the center bore of the nozzleinsulator 335 is provided with threads and the nozzle insulator 335 isthreadably mounted on the diffuser base 320. In one embodiment, thenozzle insulator 335 is constructed of a non-conductive material.

The nozzle 336 is similar to nozzles well known in the art. The nozzle336 has a first end and an open second end with a gas channel 338extending therebetween. The first end of the nozzle 336 is connected tosecond end of the nozzle insulator 335. In one embodiment, the nozzle336 is threadably secured on the nozzle insulator 335. However it isunderstood that the nozzle 336 can be secured on the nozzle insulator335 by any means well known in the art. When the nozzle 336 is securedon the nozzle insulator 335, the nozzle 336 extends outward from thefirst end along the contact tip 332 essentially along the longitudinalaxis A″-A″ of the diffuser sleeve 321 toward the second end 332B of thecontact tip 332 so that the diffuser sleeve 321 is in the gas channel338 of the nozzle 336 and the holes 330 in the diffuser portion 328 ofthe wall 328 of the diffuser sleeve 321 are in fluid communication withthe gas channel 338 of the nozzle 336. The nozzle 336 extends along thecontact tip 332 so that the contact tip 332 is in the gas channel 338.In one embodiment, the second end of the nozzle 336 extends beyond thesecond end 332B of the contact tip 332. In one embodiment, the secondend of the nozzle 336 is essentially even with the second end 332B ofthe contact tip 332. In one embodiment, the second end 332B of thecontact tip 332 extends beyond the second end of the nozzle 336. In oneembodiment, the second end of the gas channel 338 is tapered inwardtoward the contact tip 332.

In the first embodiment of the present invention, the end assembly 10 isassembled so that the second end 12B of the gooseneck 12 is securelyheld in the inner cavity 22 of the diffuser sleeve 20 at the first end20A and the contact tip 32 is securely held in the inner cavity 22 ofthe diffuser sleeve 20 at the second end 20B with the insert 40 spacedtherebetween. The second end 12B of the gooseneck 12, the diffusersleeve 20, the insert 40 and the contact tip 32, when secured togethershare a common axis forming the longitudinal axis of the end assembly 10which is substantially the longitudinal axis A-A of the diffuser sleeve20. The diffuser sleeve 20 is connected to the second end 12B of thegooseneck 12 by any means well known in the art. In one embodiment, thesecond end 12B of the gooseneck 12 is force fit into the inner cavity 22at the first end 20A of the diffuser sleeve 20. The contact tip 32 isconnected to the second end 20B of the diffuser sleeve 20 by any ofmeans well known in the art. In one embodiment, the inner cavity 22 ofthe diffuser sleeve 20 at the second end 22B has threads 31 and thefirst end 32A of the contact tip 32 has threads 32C and the contact tip32 is threadably secured in the inner cavity 22 of the diffuser sleeve20. In one embodiment, the threads 31 and 32C are buttress threads. Inone embodiment, the buttress threads 31 are created in the inner cavity22 of the diffuser sleeve 20 by tapping the diffuser sleeve 20 from thefirst end 20A prior to positioning of the insert 40 in the inner cavity22 of the diffuser sleeve 20. In one embodiment, there are four (4)buttress threads and the contact tip 32 is rotated four (4) times tosecure or remove the contact tip 32 from the diffuser sleeve 20. The useof buttress threads enables less turns of the contact tip 32 to securethe contact tip 32 in the diffuser sleeve 20. The insert 40 ispositioned and secured in the inner cavity of the diffuser sleeve 20spaced between the second end 12B of the gooseneck 12 and the first end32A of the contact tip 32. The insert 40 is positioned in the innercavity 22 of the diffuser sleeve 20 with the wall 42 of the insert 40axially adjacent the wall 28 of the diffuser sleeve 20. The insert 40can be secured in the inner cavity 22 by any means well known in theart. In one embodiment, the insert 40 is press fit in the inner cavity22 of the diffuser sleeve 20. The insert 40 is in contact with thesecond end 12B of the gooseneck 12 and the first end 32A of the contacttip 32. In one embodiment, where the contact tip 32 has a radiused endsurface 32D and the insert 40 has the indention 40C with a radiusedinner surface 40D, the diffuser sleeve 20 secures the contact tip 32 incontact with the insert 40 so that the radiused end surface 32D of thecontact tip 32 extends into the indention 40C in the second end 40B ofthe insert 40 and contacts the radiused inner surface 40D of the insert40 to increase the surface contact area between the insert 40 and thecontact tip 32. In one embodiment, the shape of the indention 40C in thesecond end 40B of the insert 40 is essentially the exact opposite of theshape of the end surface 32D of the first end 32A of the contact tip 32so that the first end 32A of the contact tip 32 fits securely into theindention 40C in the second end 40B of the insert 40 and the radiusedouter end surface 32D buts the inner surface 40D of the indention 40C.The first end 36A of the nozzle 36 is connected to the diffuser sleeve20 by any means well known in the art. The nozzle 36 is connected to thefirst portion of the diffuser sleeve 20 and extends outward towards thesecond end 32B of the contact tip 32. In one embodiment, the second end36B of the nozzle 36 is essentially even with the second end 32B of thecontact tip 32. However, it is understood that the second end 36B of thenozzle 36 can extend beyond the second end 32B of the contact tip 32 orthe second end 32B of the contact tip 32 can extend beyond the secondend 36B of the nozzle 36.

In one embodiment, the second end 12B of the gooseneck 12 is constructedof a conductive material, the insert 40 is constructed of a conductivematerial, the contact tip 32 is constructed of a conductive material andthe diffuser sleeve 20 is constructed of a poorly conductive ornon-conductive material or of a material that is less conductive thanthe material or materials used to construct the insert 40 or the contacttip 32. In one embodiment, the second end 12B of the gooseneck 12 isconstructed of copper, the insert 40 is constructed of copper, thecontact tip 32 is constructed of copper and the diffuser sleeve 20 isconstructed of brass. The diffuser sleeve 20 ensures a secure and tightfit between the gooseneck 12, the insert 40 and the contact tip 32 andensures constant contact between the second end 12B of the gooseneck 12,the insert 40 and the contact tip 32 during use of the welding device110. In one embodiment, the second end 12B of the gooseneck 12 is formedby the inner conduit 16, and the inner conduit 16 is constructed of aconductive material and the inner conduit 16 is in contact with theinsert 40. In one embodiment, the second end 12B of the gooseneck 12 isformed by the inner conduit 16, and the inner conduit 16 is constructedof copper and the inner conduit 16 is in contact with the insert 40.

In the second embodiment where the diffuser 240 is connected to thesecond end 212B of the gooseneck 212, the second end 212B of thegooseneck 212 having the diffuser 240 is inserted into the inner cavity222 of the diffuser sleeve 220 at the first end 220A and moved into theinner cavity 222 until the wall 242 of the diffuser 240 is axiallyadjacent the wall 228 of the diffuser sleeve 220. In this embodiment,the diffuser sleeve 220 can be secured on the second end 212B of thegooseneck 212 by any means well known in the art. In one embodiment, theinner cavity 222 at the first end 220A of the diffuser sleeve 220 hasthreads and second end 212B of the gooseneck 220 has threads and thethreads of the gooseneck 212 threadably mate with the threads of thediffuser sleeve 220 to securely hold the gooseneck in the diffusersleeve. The contact tip 232 is inserted into the inner cavity 222 of thediffuser sleeve 220 from the open second end 220B of the diffuser sleeve220. The contact tip 232 can be secured in the diffuser sleeve 220 byany means well known in the art. In one embodiment, the inner cavity 222at the second end 220B of the diffuser sleeve 220 has threads and firstend 232A of the contact tip 232 has threads and the threads of thecontact tip 232 threadably mate with the threads of the diffuser sleeve220 to securely hold the contact tip in the diffuser sleeve 220. In oneembodiment, the diffuser 240 is constructed of a conductive material,the contact tip 232 is constructed of a conductive material and thediffuser sleeve 220 is constructed of a poorly conductive ornon-conductive material or of a material that is less conductive thanthe material or materials used to construct the contact tip 232 or thediffuser 240. In one embodiment, the diffuser 240 is constructed ofcopper, the contact tip 232 is constructed of copper and the diffusersleeve 220 is constructed of brass. The diffuser sleeve 220 ensures asecure and tight fit between the gooseneck 212 and the contact tip 232and enables constant contact between the diffuser 240 of the gooseneck212 and the contact tip 232 during use of the welding device 110. In oneembodiment, the diffuser 240 is formed in the end of the inner conduit216 and the inner conduit 216 is constructed of a conductive materialand the inner conduit 216 is in contact with the contact tip 232. In oneembodiment, the diffuser 240 is formed in the end of the inner conduit216 and the inner conduit 216 is constructed of conductive material andthe inner conduit 216 is in contact with the contact tip 232. In oneembodiment, the diffuser 240 is formed in the end of the inner conduit216 and the inner conduit 216 is constructed of copper and the innerconduit 216 is in contact with the contact tip 232.

To construct the end assembly 310 of the third embodiment, the secondend 340B of the insert 340 is inserted into the inner cavity 320C of thediffuser base 320 through the first end 320A of the diffuser base 320.The insert 340 is inserted into the diffuser base 320 until the secondend 340B of the insert 340 extends beyond the second end 320B of thediffuser base 320 and the first end 340A of the insert 340 is completelywithin the inner cavity 320C of the diffuser base 320. In oneembodiment, the first end 340A of the insert 340 does not extendcompletely into the inner cavity 320C of the diffuser base 320 and thefirst end 340A of the insert 340 extends beyond the first end 320A ofthe diffuser base 320 in a direction opposite the second end 320B of thediffuser base 320. In this embodiment, the gooseneck is mounted on thefirst end 340A of the insert 340. The insert 340 can be secured in theinner cavity 320C of the diffuser base 320 by any means well known inthe art. In one embodiment, the first threads 342E on the first end 340Aof the insert 340 mate with the second threads 320E of the diffuser base320 and the insert 340 is threadably secured in the diffuser base 320.The diffuser sleeve 321 is positioned on the second end 340B of theinsert 340 so that the second end 340B of the insert 340 moves into theinner chamber of the diffuser sleeve 321 through the first end 321A ofthe diffuser sleeve 321. The diffuser sleeve 321 is then secured to theinsert 340. The insert 340 can be secured in the inner chamber of thediffuser sleeve 321 by any means well known in the art. In oneembodiment, the first threads 328E on the first end 321A of the diffusersleeve 321 threadably mates with the second threads 342F on the outersurface 342D of the wall 342 of the insert 340 to threadably secure theinsert 340 in the inner chamber of the diffuser sleeve 321. In oneembodiment, the insert 340 extends beyond the second end 320B of thediffuser base 320 to almost the second end 321B of the diffuser endsleeve 321. In one embodiment, the insert 340 does not extend beyond thesecond end 321B of the diffuser sleeve 321.

When the insert 340 is secured in the inner chamber of the diffusersleeve 321, the diffuser portion 328A of the wall 328 of the diffusersleeve 321 is axially adjacent the diffuser portion 342A of the wall 342of the insert 340. The diffuser portion 328A of the wall 328 of thediffuser sleeve 321 is spaced apart from the diffuser portion 342A ofthe wall 342 of the insert 340 forming a chamber 350 positioned betweenthe diffuser portion 328A of the wall 328 of the diffuser sleeve 321 andthe diffuser portion 342A of the wall 342 of the insert 340. The outersurface 342D of the diffuser portion 342A of the wall 342 of the insert340 is spaced apart from the inner surface 328C of the diffuser portion328A of the wall 328 of the diffuser sleeve 321 forming the chamber 350.In one embodiment, the outer surface 342D of the diffuser portion 342Aof the wall 342 of the insert 340 is angled along an axial length of theinsert 340 so that the chamber 350 is tapered along the axis A″-A″ andalong the length of the chamber 350. In one embodiment, the length ofthe diffuser portion 342A of the wall 342 of the insert 340 is varied tochange the length of the chamber 350. In one embodiment, the length ofthe diffuser portion 328A of the wall 328 of the diffuser sleeve 321 isvaried to change the length of the chamber 350. In one embodiment, theshape of the outer surface 342D of the diffuser portion 342A of the wall342 of the insert 340 is varied to change or adjust the shape and sizeof the chamber 350. In one embodiment, the inner surface 328C of thediffuser portion 328A of the wall 328 of the diffuser sleeve 321 isvaried to change a size and shape of the chamber 350. In one embodiment,the chamber 350 extends along the longitudinal axis A″-A″ of thediffuser sleeve 321 and the diameter of the chamber 350 adjacent thefirst end 340A of the insert 340 is less than the diameter of thechamber 350 adjacent the second end 340B of the insert 340. The holes344 in the diffuser portion 342A of the wall 342 of the insert 340 andthe holes 330 in the diffuser portion 328A of the wall 328 of thediffuser sleeve 321 are in fluid communication with the chamber 350. Inone embodiment, the insert 340 is positioned in the diffuser sleeve 321so that the holes 344 in the diffuser portion 342A of the wall 342 ofthe insert 340 are not axially aligned or are axially misaligned oraxially offset with the holes 330 in the diffuser portion 328A of thewall 328 of the diffuser sleeve 321 so that the holes 344 in thediffuser portion 342A of the wall 342 of the insert 340 are axiallyspaced apart from the holes 330 in the diffuser portion 328A of the wall328 of the diffuser sleeve 321. In one embodiment, when the insert 340is positioned in the diffuser sleeve 321, the holes 344 in the diffuserportion 342A of the wall 342 of the insert 340 and the holes 330 in thediffuser portion 328A of the wall 328 of the diffuser sleeve 321 are notin the same plane perpendicular to the longitudinal axis A″-A″ of theend assembly 310. In one embodiment, when the insert 340 is positionedin the diffuser sleeve 321, the holes 344 in the diffuser portion 342Aof the wall 342 of the insert 340 are axially positioned between thefirst end 321A of the diffuser sleeve 321 and the holes 330 in thediffuser portion 328A of the wall 328 of the diffuser sleeve 321. Inanother embodiment, when the insert 340 is positioned in the diffusersleeve 321, the holes 330 in the diffuser portion 328A of the wall 328of the diffuser sleeve 321 are axially positioned between the first end321A of the diffuser sleeve 321 and the holes 344 in the diffuserportion 342A of the wall 342 of the insert 340. In one embodiment, thediameter of the holes 330 in the diffuser portion 328A of the wall 328of the diffuser sleeve 321 is greater than the diameter of the holes 344in the diffuser portion 342A of the wall 342 of the insert 340. In oneembodiment, the diameter of the holes 330 in the diffuser portion of thewall 328 of the diffuser sleeve 321 is less than the diameter of theholes 344 in the diffuser portion 342A of the wall 342 of the insert340. In one embodiment, the diameter of the holes 330 in the diffuserportion 328A of the wall 328 of the diffuser sleeve 321 is essentiallyequal to the diameter of the holes 344 in the diffuser portion 342A ofthe wall 342 of the insert 340. In one embodiment, the number of holes330 in the diffuser portion 328A of the wall 328 of the diffuser sleeve321 is equal to the number of holes 344 in the diffuser portion 342A ofthe wall 342 of the insert 340. In one embodiment, the number of holes330 in the diffuser portion 328A of the wall 328 of the diffuser sleeve321 is less than the number of holes 344 in the diffuser portion 342A ofthe wall 342 of the insert 340. In one embodiment, the number of holes330 diffuser portion 328A in the wall 328 of the diffuser sleeve 321 isgreater than the number of holes 344 in the diffuser portion 342A of thewall 342 of the insert 340. It is understood that the number anddiameter of the holes 330 in the diffuser portion 328A of the wall 328of the diffuser sleeve 321 and the number and diameter of the holes 344in the diffuser portion 342A of the wall 342 of the insert 340 can varydepending on the use of the end assembly 310, the type of gas usedduring welding, the material used to construct the contact tip 332, thematerial used to construct the insert 340 and the amount of current usedduring welding as well as other variables.

Once the insert 340 is secured in the diffuser sleeve 321, the contacttip 332 is connected to the second end 321B of the diffuser sleeve 321.The contact tip 332 is secured in the diffuser sleeve 321 so that theouter end surface 332D of the tapered or radiused first end 332A of thecontact tip 332 is securely in contact with the inner surface of theindention 340C in the second end 340B of the insert 340 and so that thecenter bore 334 of the contact tip 332 is aligned with the secondsection 346C of the inner passageway 346 of the insert 340. Once thecontact tip 332 is secured in the inner chamber of the diffuser sleeve321, the nozzle 336 can be secured onto the diffuser sleeve 321. The endassembly 310 is mounted on the second end of the gooseneck so that theinner conduit of the gooseneck is in contact with the first end 340A ofthe insert 340.

The end assembly 10 of the present invention is secured to the weldingdevice 110 for use in a welding system 100. The welding system 100 isactivated such that the electrode 116 moves from the electrode supply104 through the passageway of the gooseneck 12 through the innerpassageway 46 of the insert 40 and through the center bore 34 of thecontact tip 32 toward the workpiece 120. In the second embodiment, theelectrode 116 moves through the passageway 214 of the gooseneck 212through the diffuser 240 and through the center bore 234 of the contacttip 232 toward the workpiece 120. In the third embodiment, the electrode116 moves through the inner cavity 320C of the diffuser base 320,through the inner passageway 346 of the insert 340 and through thecenter bore 334 of the contact tip 332 toward the workpiece 120. In oneembodiment, the electrode 116 is a weld wire similar to weld wires wellknown in the art. As the electrode 116 moves through the end assembly10, the gas 118 flows from the gas supply 102 through the passageway 14of the gooseneck 12 to the inner passageway 46 of the insert 40. The gas118 flows from the first section 46A of the inner passageway 46 into thediffuser section 46B of the inner passageway 46 of the insert 40. Thegas 118 exits the diffuser section 46B and flows out the hole or holes44 in the wall 42 of the insert 40 into the chamber 50. In the secondembodiment, the gas 118 flows from the gas supply 102 through thepassageway 214 of the gooseneck 212 into the inner passageway 246 of thediffuser 240 and exits through the inner passageway 246 through the holeor holes 244 in the wall 242 of the diffuser 240 into the chamber 250.In the third embodiment, the gas 118 flows from the gas supply 102through the passageway of the gooseneck into the inner cavity 320C ofthe diffuser base 320 and into the inner passageway 346 of the insert340. The gas 118 flows from the first section 346A of the innerpassageway 346 into the diffuser section 346B of the inner passageway346 of the insert 340. The gas exits the inner passageway 346 throughthe hole or holes 344 in the diffuser section 342A of the wall 342 ofthe insert 340 and into the chamber 350. The gas 118 is trapped ortemporarily held in the chamber 50, 250 or 350 before exiting thechamber 50, 250 or 350 through the hole or holes 30, 230, 330 in thewall 28, 228 or 328 of the diffuser sleeve 20 or 220 or diffuser sleeve321and into the gas channel 38 or 238 of the nozzle 36, 236 or 236. Thegas 118 flows along the gas channel 38 or 238 of the nozzle 36, 236 or336 to the open, second end 36B or 236B of the nozzle 36, 236 or 336 andaround electrode 116 and the weld puddle on the workpiece 120. The sizeand the shape of the chamber 50, 250 or 350, the positioning, the numberand the diameter of the hole or holes 44 in the wall 42 of the insert40, or in the second embodiment the hole or holes 244 in the wall 242 ofthe diffuser 240, or in the third embodiment the hole or holes 344 inthe diffuser portion 342A of the wall 342 of the insert 340 and thepositioning, the number and the diameter of the hole or holes 30, 230 or330 in the wall 28, 228 or 328 of the diffuser sleeve 20, 220 or 321 canbe adjusted or changed to control the movement of the gas 118 trapped inthe chamber 50, 250 or 350 and the flow of gas 118 exiting the chamber50, 250 or 350. In one embodiment, the size and shape of the chamber 50,250, or 350, the positioning, the number and the diameter of the hole orholes 44 in the wall 42 of the insert 40, or in the second embodimentthe hole or holes 244 in the wall 242 of the diffuser 240, or in thethird embodiment the hole or holes 344 in the diffuser portion 342A ofthe wall 342 of the insert 340 and the positioning, the number and thediameter of the hole or holes 30, 230 or 330 in the wall 28 or 228 ofthe diffuser sleeve 20 or 220 or diffuser portion 328A of the wall 328of the diffuser sleeve 321 are adjusted or changed to control thevelocity of the gas 118 in the chamber 50, 250 or 350. In oneembodiment, the size and shape of the chamber 50, 250 or 350, thepositioning, the number and the diameter of the hole or holes 44 in thewall 42 of the insert 40, or in the second embodiment the hole or holes244 in the wall 242 of the diffuser 240, or in the third embodiment thehole or holes 344 in the diffuser portion 342A of the wall 342 of theinsert 340 and the positioning, the number and the diameter of the holeor holes 30 or 230 in the wall 28 or 228 of the diffuser sleeve 20 or220 or in the diffuser portion 328A of the wall 328 of the diffusersleeve 321 are adjusted or changed to control the velocity of the gas118 exiting the chamber 50, 250 or 350. In one embodiment, increasing alength of the chamber 50, 250 or 350 increases the velocity of the gas118 held in the chamber 50, 250 or 350. In one embodiment, the chamber50, 250 or 350 is tapered along the length so that a size or diameter ofthe chamber 50, 250 or 350 adjacent the first end 20A or 220A of thediffuser sleeve 20 or 220 or first end 321A of the diffuser sleeve 321is smaller or less than the size or diameter of the chamber 50, 250 or350 adjacent the second end 20B or 220B of the diffuser sleeve 20 or 220or second end 321B of the diffuser sleeve 321. By controlling themovement of the gas 118 trapped in the chamber 50, 250 or 350 and bycontrolling the flow of gas 118 exiting the chamber 50, 250 or 350 intothe gas channel 38, 238 or 338 of the nozzle 36, 236 or 336, the flow ofgas 118 around the contact tip 32, 232 or 332 and exiting the open,second end 36B or 236B of the nozzle 36, 236 or 336 is controlled. Inone embodiment, the velocity of the gas 118 exiting the chamber 50, 250or 350 into the gas channel 38, 238 or 338 of the nozzle 36, 236 or 336is greater than the velocity of the gas 118 entering the chamber 50, 250or 350. By trapping or holding the gas 118 in the chamber 50, 250 or 350and controlling the movement of the gas 118 in the chamber 50, 250 or350, the flow of gas 118 through the gas channel 38, 238 or 338 of thenozzle 36, 236 or 336 is less turbulent which results in less turbulencein the flow of gas 118 exiting the second end 36B or 236B of the nozzle36, 236 or 336 which results in a less turbulence and a more controlledflow of gas 118 around the weld puddle (FIG. 12 ). Controlling the flowof gas 118 around the weld puddle produces a more controlled atmospherearound the weld puddle which reduces the introduction of contaminantsinto the flow of gas 118 and into the weld puddle which produces abetter weld. The flow of gas 118 in the end assembly 10, 210 or 310 iscontrolled such that the flow of gas 118 is evenly distributed aroundthe contact tip 32, 232 or 332 as the gas 118 moves through the gaschannel 38, 238 or 338 of the nozzle 36, 236 or 336 which allows for aneven distribution of gas 118 out the second end 36B or 236B of thenozzle 36, 236 or 336 and around the electrode 116 and the weld puddle.Controlling the flow of gas 118 also reduces the amount of gas 118 usedduring welding. In one embodiment, the second end 32B, 232B or 332B ofthe contact tip 32, 232 or 332 is rounded which results in lessdisturbance of the flow of gas 118 as it exits the second end 36B or236B of the nozzle 36, 236 or 336 which results in less turbulence andmore controlled flow of gas 118 around the weld puddle. Trapping orholding the gas 118 in the chamber 50, 250 or 350 around the insert 40or around the diffuser 240 or the insert 340, also acts to cool theinsert 40, diffuser 240 or insert 340 and the contact tip 32, 232 or332. Cooling of the contact tip 32, 232 or 332 slows the annealing ofthe contact tip 32, 232 or 332 which results in a longer useful life forthe contact tip 32, 232 or 332.

In one embodiment, the second end 12B of the gooseneck 12, the insert 40and the contact tip 32 are constructed of a conductive material and thediffuser sleeve 20 is constructed of a poorly conductive ornon-conductive material or of a material less conductive than thematerial or materials used to construct the insert 40 or the contact tip32. In one embodiment, the second end 12B of the gooseneck 12, theinsert 40 and the contact tip 32 are constructed of copper and thediffuser sleeve 20 is constructed of a poorly conductive ornon-conductive material or a material that is less conductive thancopper. In one embodiment the second end 12B of the gooseneck 12, theinsert 40 and the contact tip 32 are constructed of copper and thediffuser sleeve 20 is constructed of brass. The diffuser sleeve 20securely holds the contact tip 32 in contact with the insert 40 and theinsert 40 in contact with the second end 12B of the gooseneck 12 duringuse of the welding device 110. The diffuser sleeve 20 securely holds thecontact tip 32, insert 40 and second end 12B of the gooseneck 12 inposition which allows for good conductivity between second end 12B ofthe gooseneck 12, the insert 40 and the contact tip 32. The gas 118trapped in the chamber 50 around the wall 42 of the insert 40 cools theinsert 40 which reduces the temperature of the insert 40 and the contacttip 32 and prevents the insert 40 and contact tip 32 from fusingtogether. The cooling of the insert 40 by the gas 118 trapped in thechamber 50 also pulls heat away from the contact tip 32 which is incontact with the insert 40 which reduces the heat of the contact tip 32during use and extends the life of the contact tip 32.

In one embodiment of the second embodiment, the diffuser 240 and thecontact tip 232 are constructed of a conductive material and thediffuser sleeve 220 is constructed of a poorly conductive ornon-conductive material or a material that is less conductive than thematerial or materials used to construct the diffuser 240 or the contacttip 232. In one embodiment of the second embodiment, the diffuser 240and the contact tip 232 are constructed of copper and the diffusersleeve 220 is constructed of a poorly conductive or non-conductivematerial or of a material less conductive than copper. In one embodimentof the second embodiment, the diffuser 240 and the contact tip 232 areconstructed of copper and the diffuser sleeve 220 is constructed of abrass. The diffuser sleeve 220 securely holds the contact tip 232 incontact with the diffuser 240 allowing for good conductivity betweendiffuser 240 and the contact tip 232 during use of the welding device110. The gas 118 trapped in the chamber 250 acts to cool the diffuser240 which reduces the heat of the diffuser 240 and prevents the diffuser240 and the contact tip 232 from fusing together. The gas 118 trapped inthe chamber 250 cools the diffuser 240 and pulls heat away from thecontact tip 232 which is in contact with the diffuser 240 which reducesthe heat of the contact tip 232 during use and extends the life of thecontact tip 232.

In one embodiment of the third embodiment, the inner conduit of thegooseneck, the insert 340 and the contact tip 332 are constructed of aconductive material and the diffuser sleeve 321 and the diffuser base320 are constructed of a poorly conductive or non-conductive material ora material less conductive than the material or materials used toconstruct the insert 340 or the contact tip 332. In one embodiment, theinner conduit of the gooseneck, the insert 340 and the contact tip 332are constructed of copper and the diffuser sleeve 321 and diffuser base320 are constructed of a poorly conductive, less conductive ornon-conductive material. In one embodiment, the diffuser sleeve 321 andthe diffuser base 320 are constructed as a unitary piece. In oneembodiment the inner conduit of the gooseneck, the insert 340 and thecontact tip 332 are constructed of copper and the diffuser sleeve 321and the diffuser base 320 are constructed of brass. The diffuser sleeve321 securely holds the contact tip 332 in contact with the insert 340and the diffuser base 320 securely holds the insert 340 in contact withthe second end of the gooseneck during use of the welding device 110.The diffuser sleeve 321 and the diffuser base 320 securely hold thecontact tip 332, insert 340 and second end of the gooseneck in positionwhich allows for good conductivity between second end of the gooseneck,the insert 340 and the contact tip 332. The gas 118 trapped in thechamber 350 around the diffuser portion 342A of the wall 342 of theinsert 340 cools the insert 340 which reduces the temperature of theinsert 340 and the contact tip 332 and prevents the insert 340 andcontact tip 332 from fusing together. The cooling of the insert 340 bythe gas 118 trapped in the chamber 350 also pulls heat away from thecontact tip 332 which is in contact with the insert 340 which reducesthe heat of the contact tip 332 during use and extends the life of thecontact tip 332.

Increasing the contact area between the contact tip 32, 232 or 332 andthe insert 40, or the diffuser 240 or insert 340 increases the coolingeffect of the trapped gas 118 on the contact tip 32, 232 or 332 throughthe insert 40, the diffuser 240 or the insert 340. In one embodimentwhere the contact tip 32 or 332 has a radiused end surface 32D or 332Dand the insert 40 or insert 340 has the indention 40C or 340C with aradiused inner surface 40D, the diffuser sleeve 20 or diffuser sleeve321 secures the contact tip 32 or 332 in contact with the insert 40 orinsert 340 so that the radiused end surface 32D or 332D of the contacttip 32 or 332 extends into the indention 40C or 340C in the second end40B or 340B of the insert 40 or insert 340 and contacts the radiusedinner surface 40D of the insert 40 or insert 340 to increase the area ofsurface contact between the insert 40 or insert 340and the contact tip32 or 332 (FIG. 3 ). In the second embodiment where the diffuser 240extends into the indention 232C in the first end 232A of the contact tip232 such that the end surface of the diffuser 240 is in contact with theinner surface 232D of the indention 232C of the contact tip 232, theincreased surface contact between the diffuser 240 and the contact tip232 assists in moving the heat away from the contact tip 232 through thediffuser 240 as the gas 118 trapped in the chamber 250 cools thediffuser 240 which prevents the contact tip 232 from fusing with thediffuser 240 (FIG. 11 ).

In the embodiments where the second end 12B of the gooseneck 12, theinsert 40 or insert 340 and the contact tip 32 or 332 are constructed ofa conductive material with the gooseneck 12, the insert 40 or insert 340and the contact tip 32 or 332 securely held together in constant contactby the diffuser sleeve 20 or 321 constructed of a poorly conductive ornon-conductive material or less conductive material, the flow of currentthough the electrode 116 from the power supply 106 to the workpiece 120has less resistance or less impedance which reduces the amount of energyused during the welding process. Similarly in the second embodimentwhere the diffuser 240 and the contact tip 232 are constructed of aconductive material and are securely held in constant contact by thediffuser sleeve 220 constructed of a poorly conductive or non-conductivematerial or less conductive material, the flow of current though theelectrode 116 from the power supply 106 to the workpiece 120 has lessresistance or less impedance which reduces the amount of energy usedduring the welding process. Constructing the insert 40, the diffuser 240or the insert 340 from a conductive material provides betterconductivity throughout the end assembly 10, 210 or 310 allowing for aconsistence flow of current through the end assembly 10,210 or 310 whichreduces impedance during the welding and allows for consistent arcstarting and results in less false arc starts. Reducing false arc startsand ensuring good, clean arc starting results in more efficient weldingand less energy usage during welding. Constructing the insert 40 or 340,the diffuser 240 from a conductive material also provides lessresistance or less impedance to the current flow which allows for highercurrent flow through the end assembly 10, 210 or 310 before overheatingof the end assembly 10, 210 or 310 which acts to reduce damage to theend assembly 10, 210 or 310 during high welding.

In the foregoing description, various features of the present inventionare grouped together in one or more embodiments for the purpose ofstreamlining the disclosure. This method of disclosure is not to beinterpreted as reflecting an intention that the claimed inventionrequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated by reference herein in their entirety,with each claim standing on its own as a separate embodiment of thepresent invention.

It is intended that the foregoing description be only illustrative ofthe present invention and that the present invention be limited only bythe hereinafter appended claims.

We claim:
 1. A welding apparatus comprising: a contact tip configured tobe received in an inner cavity of an end assembly of a welding system,the contact tip defining a bore extending therethrough from a first endto a second end and configured for guiding a weld wire into the firstend and out of the second end during a welding operation, wherein thefirst end has a convex and curved outer surface; wherein the first endof the contact tip is configured for being received into an indentation,the indentation having a concave and curved inner surface correspondingin shape to the convex and curved outer surface of the contact tip,wherein the convex and curved outer surface of the contact tip isconfigured to abut the concave and curved inner surface of theindentation; wherein the contact tip is a single piece and includes anexternal fastening portion extending radially outward therefrom; whereinthe contact tip includes a non-threaded end portion extending axiallyaway from the external fastening portion of the contact tip, wherein thenon-threaded end portion includes the convex and curved outer surface.2. The welding apparatus of claim 1, further comprising: a diffusordefining the inner cavity, wherein the contact tip is received in theinner cavity; wherein the external fastening portion comprises externalthreads; wherein the diffuser includes a plurality of internal threads;wherein the external threads of the contact tip directly contact andthreadingly engage the internal threads of the diffuser sleeve.
 3. Thewelding apparatus of claim 2, wherein the indentation is disposed in theinner cavity of the diffusor.
 4. The welding apparatus of claim 3,wherein threaded engagement of the contact tip with the diffusor sleevecompresses the curved outer surface of the contact tip into abuttingrelationship with the curved inner surface of the indentation inresponse to rotation of the external threads relative to the internalthreads.
 5. The welding apparatus of claim 4 wherein the curved outersurface of the contact tip matches the curved inner surface of theindentation.
 6. The welding apparatus of claim 4 wherein the curvedouter surface of the contact tip fully contacts the curved inner surfaceof the indentation.
 7. The welding apparatus of claim 2, wherein theexternal threads of the contact tip and the internal threads of thediffuser sleeve are buttress threads.
 8. A welding apparatus comprising:a contact tip configured for being installed in an inner cavity of adiffuser sleeve so that the contact tip extends into the inner cavity ofthe diffuser sleeve and extends outward from the diffuser sleeve wheninstalled in the diffuser sleeve, the contact tip having a first endwith a convex and curved outer mating surface wherein the first end ofthe contact tip extends into an indentation when installed in thediffuser sleeve, wherein the contact tip is a single piece and includesa fastening element extending radially outward therefrom; wherein thefirst end of the contact tip having the outer mating surface defines anopening having a perimeter, wherein the perimeter of the opening definesa terminal end of the convex and curved outer mating surface of thecontact tip, wherein the outer mating surface intersects the perimeterof the opening along a curved path.
 9. The welding apparatus of claim 8further comprising a diffuser sleeve having an inner cavity, theindentation disposed within the diffuser sleeve, the indentation havinga concave and curved inner surface corresponding in shape to the outermating surface of the contact tip.
 10. The welding apparatus of claim 9,wherein the diffuser sleeve includes a plurality of internal threads,wherein the external threads of the contact tip directly contact andthreadingly engage the internal threads of the diffuser sleeve andcompress the convex and curved outer mating surface of the contact tipinto abutting relationship with the concave and curved inner surface ofthe indentation in response to rotation of the external threads relativeto the internal threads.
 11. A welding apparatus comprising: a contacttip having a first end with a convex and curved end portion wherein thefirst end of the contact tip is configured to abut a correspondingconcave and curved surface of an indentation of an end assembly of awelding system, the contact tip having a second end configured for aweld wire to exit during a welding operation; a central bore extendinglongitudinally through the contact tip between the first end and thesecond end and defining a central longitudinal axis; wherein the contacttip is a single piece and includes a fastening element extendingradially outward therefrom; wherein the convex and curved end portiondefines a curved path through a cross-sectional plane that is parallelto the longitudinal axis and includes the longitudinal axis.
 12. Thewelding apparatus of claim 11 further comprising a diffuser sleeveextending longitudinally between a first and second end thereof, thediffuser sleeve including a plurality of internal threads, wherein thefastening element includes external threads that directly contact andthreadingly engage the internal threads of the diffuser sleeve.
 13. Thewelding apparatus of claim 12, wherein the indentation is disposedwithin the diffuser sleeve, wherein threaded engagement between thecontact tip and the diffuser sleeve compresses the convex and curved endportion of the contact tip into abutting relationship with the concaveand curved inner surface of the indentation in response to rotation ofthe external threads relative to the internal threads.
 14. The weldingapparatus of claim 13 wherein the convex and curved end portion of thecontact tip matches the curved inner surface of the indentation.
 15. Thewelding apparatus of claim 13 wherein the curved end portion of thecontact tip fully contacts the curved inner surface of the indentation.16. The welding apparatus of claim 11, wherein the fastening elementcloser to the first end of the contact tip than the second end of thecontact tip.
 17. The welding apparatus of claim 11, wherein the contacttip includes a first non-threaded portion extending axially away fromthe fastening element of the contact tip in a first direction, whereinthe first non-threaded end portion includes the convex and curved endportion, and wherein the contact tip includes a second non-threadedportion extending axially away from the fastening element of thecontract tip in a second direction opposite the first direction.
 18. Thewelding apparatus of claim 12, wherein the external threads of thecontact tip and the internal threads of the diffuser sleeve are buttressthreads.
 19. The welding apparatus of claim 11, wherein the convex andcurved end portion is pressed into engagement with a correspondingconcave and curved inner portion of a welding assembly when fastened inthe end assembly.
 20. The welding apparatus of claim 11, wherein aradius of the end portion varies along the curved path of the convex andcurved end surface.
 21. An end assembly for a welding device comprisinga gooseneck having a passageway; a diffuser sleeve having a first endand a second end with a longitudinal axis extending therebetween, havingan inner cavity and having a wall having a hole, the diffuser sleeveconnected to the gooseneck, a contact tip positioned in the inner cavityof the diffuser sleeve so that the contact tip extends into the innercavity of the diffuser sleeve and extends outward from the diffusersleeve, the contact tip having a first end with a convex and curvedouter surface wherein the first end of the contact tip extends into anindentation, the indentation having a concave and curved inner surfacecorresponding in shape to the convex and curved outer surface of thecontact tip, wherein the convex and curved outer surface of the contacttip abuts the concave and curved inner surface of the indentation; anozzle having a gas channel and extending outward relative to thegooseneck in a direction opposite the gooseneck; wherein the contact tipis a single piece and includes a fastening element extending radiallyoutward therefrom; wherein the diffuser sleeve includes the indentation;wherein the end assembly compresses the convex and curved outer surfaceof the contact tip into abutting relationship with the concave andcurved inner surface of the indentation when the contact tip is fastenedtherein; wherein the contact tip includes a non-threaded end portionextending axially away from the fastening element of the contact tip,wherein the non-threaded end portion includes the convex and curvedouter surface.
 22. The end assembly of claim 21 wherein the curved outersurface of the contact tip matches the curved inner surface of theindentation.
 23. The end assembly of claim 21 wherein the curved outersurface of the contact tip fully contacts the curved inner surface ofthe indentation.
 24. The end assembly of claim 21, wherein the convexand curved outer surface defines a curved path through a cross-sectionalplane that is parallel to the longitudinal axis and includes thelongitudinal axis.
 25. The end assembly of claim 21, wherein the firstend of the contact tip defines an opening having a perimeter, whereinthe perimeter of the opening defines a terminal end of the convex andcurved outer surface of the contact tip, wherein the convex and curvedouter surface intersects the perimeter of the opening along a curvedpath.